The Size of the Problem: How One Platform Is Fixing Fashion's £2bn Information Failure

A British startup has built the world's largest clothing sizing database. Its success reveals how information asymmetry plagues online retail—and why solving it matters for sustainability

Fashion & Technology | October 2025

The fashion industry has a £2 billion problem, and it is startlingly simple: nobody knows what size they are. Or rather, everybody knows what size they think they are, which turns out to be worse than not knowing at all. A shopper who confidently orders a size 10 dress discovers, upon delivery, that she needs a size 14 in Brand A but a size 8 in Brand B, and probably shouldn't order from Brand C at all because their sizing bears no relation to her body's actual dimensions. The result is a staggering 30-40% return rate for online fashion purchases in Britain alone, with sizing issues causing roughly half of those returns.

This is, in economic terms, a textbook case of information asymmetry. Consumers lack reliable information about how clothing will fit, leading to inefficient transactions, significant deadweight loss, and environmental externalities that would make even the most jaded economist wince. Enter Tellar, a London-based platform that has spent two years building what it claims is the world's largest free clothing sizing database—covering 1,500 brands and accessible to any consumer with internet access. The company has, in effect, attempted to solve a market failure through what economists might call information aggregation and dissemination, though its founders would probably just say they got tired of returning ill-fitting clothes.

The economics of guessing wrong

To understand why Tellar matters, one must first appreciate the staggering economic inefficiency of the current system. Online fashion retail in Britain generates approximately £20 billion in sales annually. With return rates hovering around 35% and roughly half of those returns attributable to sizing issues, British consumers are returning approximately £3.5 billion worth of clothing due to poor fit. Factor in the cost of processing these returns—estimated at £1.5-2 billion annually when one accounts for logistics, quality checking, repackaging, and the 15% of returned items ultimately destroyed—and the scale of the problem becomes clear.

This is not, it should be noted, a problem of consumer irrationality. Quite the opposite: consumers are behaving perfectly rationally in response to profound information asymmetry. When a size 10 label can represent measurements ranging from 32 to 36 inches in the bust (a variation Tellar's research has documented), the rational response is to order multiple sizes and return those that don't fit. Economists call this "bracketing," and while it makes sense for the individual consumer, it creates enormous collective inefficiency.

The environmental costs add another dimension. Each return journey generates approximately 20kg of CO2 emissions. With an estimated 120 million items returned annually in Britain due to sizing issues, that's 2.4 million tonnes of carbon—equivalent to the annual emissions of a small city. If one believes that carbon emissions carry significant negative externalities (and most economists do, even if they quibble about the precise social cost), then solving the sizing problem begins to look less like a convenience feature and more like a meaningful contribution to sustainability.

The information arbitrage

Tellar's solution is conceptually straightforward: aggregate sizing information from every major fashion brand, standardize it, and make it freely accessible. In practice, this proved rather more difficult. The company spent two years systematically collecting size charts from 1,500 brands, verifying their accuracy through sample purchases and physical measurements, and building an algorithm that matches a consumer's body measurements to the appropriate size in any given brand. The database now contains 50,000 distinct data points, updated quarterly, covering everything from British high-street retailers to American fast-fashion brands to European luxury labels.

The economic value proposition is clear. By providing perfect information (or as close to it as is practically achievable given manufacturing variance), Tellar eliminates the guesswork that drives return rates. The company claims that users who follow its recommendations experience a 67% reduction in returns—a figure that, if replicated at scale, would save British retailers approximately £1.2 billion annually in logistics costs alone.

What makes Tellar particularly interesting from an economic perspective is its business model, or rather, its studied avoidance of the business models one might expect. The platform is free to use, charges no subscription fees, displays no advertising, and accepts no sponsored content. Instead, it relies on affiliate commissions: when a user clicks through to a retailer and makes a purchase, Tellar receives a small percentage (typically 3-10%) from the retailer's existing marketing budget. This creates what economists might recognize as an incentive alignment: Tellar succeeds only when users successfully purchase items that fit, which means accuracy, not sales volume, drives the business model.

The competitive void

Perhaps the most surprising aspect of Tellar's position is how little competition it faces. A survey of the global market for clothing sizing technology reveals a fragmented landscape in which no other platform offers comparable breadth, accessibility, or independence. Subscription-based sizing services exist but cover far fewer brands (typically fewer than 200) and cost £5-15 monthly, creating a barrier to entry that excludes the very consumers who most need help making smart purchases: those on tight budgets. Enterprise B2B solutions like True Fit and Fits.me serve retailers rather than consumers, selling their technology for tens of thousands of dollars annually and thus remaining inaccessible to individual shoppers seeking cross-brand comparison.

The competitive void exists for comprehensible reasons. Building a database of 1,500 brands requires approximately 4,500-6,000 hours of data collection, plus the development of systems for verification, maintenance, and updates. The barriers to entry are formidable: significant time investment, technical expertise, ongoing operational costs, and the challenge of achieving sufficient scale before running out of resources. Most platforms give up after covering 20-30 brands, at which point they have created a niche product useful for specific shopping occasions but inadequate as a comprehensive solution.

Tellar's first-mover advantage in comprehensive free sizing thus appears sustainable. Even if a competitor began building a comparable database today, it would require two years to reach parity with Tellar's current coverage—by which time Tellar will presumably have expanded to 2,000+ brands and strengthened its network effects. The economics resemble those of other platform businesses: high fixed costs to build the platform, low marginal costs to serve additional users, and increasing returns to scale as the user base grows.

The platform economics

Tellar's business model exhibits several characteristics that economists associate with successful platform businesses. The first is the two-sided market structure: Tellar connects consumers (who want accurate sizing information) with retailers (who want to reduce returns and increase customer satisfaction). Both sides benefit from the platform's existence, though only one side (retailers, through affiliate commissions) pays for it.

The second characteristic is network effects, though of a somewhat unusual variety. Traditional network effects—where each additional user makes the platform more valuable to other users—apply only indirectly. Tellar's value to an individual user comes primarily from the breadth of its brand coverage, not the size of its user base. However, a larger user base does generate more feedback data, which Tellar uses to refine its recommendations and identify when brands have changed their sizing. This creates a form of data network effect: more users generate better data, which improves the service, which attracts more users.

The third characteristic is the high fixed costs and low marginal costs typical of information goods. Building the initial database required substantial investment in time and human capital. But once built, serving an additional user costs Tellar almost nothing—just the computational resources to run a database query and display results. This cost structure means Tellar's profitability should improve dramatically as its user base scales, assuming the affiliate model generates sufficient revenue to cover fixed costs.

The sustainability of this model depends on several factors. Affiliate commissions must be sufficient to cover ongoing operations (database maintenance, platform development, team salaries). The company must maintain its editorial independence—the firewall preventing commercial considerations from influencing recommendations—or risk destroying user trust. And it must continue expanding brand coverage fast enough to prevent competitors from establishing a foothold in underserved niches.

The information asymmetry puzzle

From an economic perspective, Tellar is solving a textbook information asymmetry problem. Consumers and retailers have access to different information: retailers know exactly how their size 10 actually measures, while consumers have only the vague label "size 10" to guide their decisions. This information gap leads to inefficient outcomes: excessive returns, wasted resources, and suboptimal matching between consumers and products.

What makes the persistence of this information asymmetry puzzling is that, in theory, market mechanisms should have addressed it long ago. Retailers have strong incentives to provide accurate sizing information—returns are expensive, after all—and consumers desperately want this information. So why hasn't the market solved this problem on its own?

The answer appears to lie in coordination failures and conflicting incentives. Individual retailers have no incentive to help consumers comparison-shop across brands; indeed, they have reason to make such comparison difficult. Providing perfect sizing information might reduce returns, but it might also help consumers discover that a competitor's products fit them better. This creates a classic prisoner's dilemma: all retailers would collectively benefit from accurate, standardized sizing information, but each individual retailer benefits more from maintaining the status quo.

Tellar solves this coordination problem by operating as an independent third party with no loyalty to any particular retailer. Its incentive is to provide accurate information regardless of which brand ultimately makes the sale. This independence—enforced through an organizational structure that prevents the commercial team from influencing editorial decisions—is crucial to the economic function Tellar serves. Without it, the platform would simply be another marketing channel rather than a genuine information intermediary.

The vanity sizing trap

Another factor preventing market-based solutions is what might be called the vanity sizing trap. Fashion retailers have discovered that customers feel good about buying smaller size numbers, so they've gradually inflated sizing over the past two decades. What was labeled a size 12 in 2000 might now be labeled a size 8, despite identical measurements. This "size inflation" appeals to individual psychology but creates collective confusion.

Tellar's research—based on analyzing historical catalogs and contemporary size charts—found that UK size 10 measurements have increased by an average of 2.4 inches in the waist since 2000. American sizing shows even more dramatic inflation, with a contemporary US size 8 measuring approximately 2-3 sizes larger than a US size 8 from the 1990s. This represents a fascinating case of market failure: individual retailers engaging in vanity sizing gain a competitive advantage (customers prefer shopping where they fit into smaller sizes), but the collective effect is to make all size labels meaningless.

The tragedy of the commons parallel is instructive. Each retailer's vanity sizing is analogous to overfishing: individually rational, collectively destructive. Just as overfishing depletes the common resource (fish stocks), vanity sizing depletes the common resource of size label meaning. And just as overfishing creates a prisoner's dilemma requiring external intervention, solving the vanity sizing problem requires an independent actor—like Tellar—who benefits from accuracy rather than flattery.

The returns racket

The economic waste from excessive returns extends beyond the obvious logistics costs. There are subtler inefficiencies worth considering. Retailers typically price their goods to account for expected return rates; in effect, consumers who purchase items that fit subsidize those who engage in bracketing. This cross-subsidy is economically inefficient: it transfers resources from decisive purchasers to indecisive ones, and from those whose bodies happen to match standard sizing to those whose bodies don't.

The environmental externalities deserve closer examination. Academic research suggests that e-commerce, despite its apparent efficiency, may generate higher carbon emissions than traditional retail when return rates are high. A study by researchers at MIT found that the carbon footprint of a product purchased online and then returned can be 2-3 times higher than purchasing the same product in a physical store. With fashion return rates exceeding 35%, the environmental case for reducing returns becomes compelling.

Tellar's economic value proposition thus extends beyond consumer convenience. If the platform can reduce return rates by 50-67% as claimed, it would deliver genuine economic efficiency gains: lower costs for retailers, better resource allocation, reduced deadweight loss, and meaningful environmental benefits. The challenge, of course, is whether this value proposition translates into a sustainable business model that captures enough of the value created to fund ongoing operations.

The free rider problem

Tellar's decision to offer its service free raises an interesting economic question: who captures the value? The company creates significant value for multiple parties—consumers save time and money, retailers reduce return costs, the environment benefits from fewer wasted shipments—but Tellar captures only a small fraction through affiliate commissions. This creates potential free rider problems.

Consider retailers: they benefit enormously from Tellar's existence (reduced returns, better customer satisfaction) but pay only when Tellar drives a sale. Retailers whose customers use Tellar but purchase directly through brand websites capture all the benefits while contributing nothing to Tellar's sustainability. This free rider problem is endemic to information goods and platform businesses: the positive externalities are diffuse while the costs are concentrated.

The affiliate model partially addresses this by ensuring Tellar captures some value from successful transactions. But it's an imperfect solution. Tellar might create £10 of value for a retailer (reduced return processing costs) but capture only £1 in affiliate commission from that transaction. Economic theory suggests that in such situations, underinvestment is likely: Tellar might invest less in improving its service than would be socially optimal because it cannot capture the full social benefit.

This raises the question of whether alternative business models might be more efficient. A subscription model would ensure that users who benefit most pay proportionally more, but it would also exclude budget-conscious consumers—creating equity concerns and reducing the platform's scale. A B2B model, selling directly to retailers, would eliminate free rider problems but might compromise editorial independence. Advertising would monetize attention but degrade user experience and potentially influence content. Tellar's chosen model—affiliate commissions with strict editorial firewall—represents a pragmatic compromise rather than a theoretically optimal solution.

The data monopoly question

As Tellar's database becomes increasingly comprehensive and its user base grows, questions of market power inevitably arise. The company is accumulating significant information capital: not just the size chart database (which competitors could theoretically replicate given sufficient time and resources) but also behavioral data about which recommendations prove accurate, which brands have inconsistent sizing, and which measurements predict successful purchases across different body types.

This creates potential concerns about data monopoly. If Tellar becomes the dominant platform for clothing sizing information, it will exercise significant market power in determining which brands consumers consider and, potentially, in negotiating affiliate commission rates with retailers. Economic theory suggests that monopolists tend to under-produce (restricting output to maintain high prices) and may extract monopoly rents from both sides of the platform.

However, several factors constrain Tellar's potential market power. First, the company has committed to keeping the service free, which limits its ability to extract consumer surplus. Second, consumers face essentially zero switching costs: if a competitor emerged offering superior service, users could simply switch platforms. Third, Tellar's market power vis-à-vis retailers is limited by the retailers' ability to sell directly to consumers without Tellar's involvement. Fourth, the affiliate commission rates are set by networks and retailers, not by Tellar, which operates as a price-taker in that market.

The more interesting question is whether Tellar's data accumulation creates barriers to entry that prevent competition from emerging. The company's proprietary algorithm, refined over two years through user feedback, represents a genuine technical moat. The comprehensive database, requiring years to replicate, constitutes another barrier. And network effects—weak though they may be—strengthen over time. These factors suggest that Tellar's market position may prove durable, though not unassailable.

The editorial firewall puzzle

Perhaps the most economically interesting aspect of Tellar's model is its editorial firewall: the organizational structure preventing commercial considerations from influencing sizing recommendations. The company maintains that its editorial team (which creates sizing recommendations and fashion content) has no access to affiliate commission data and makes recommendations based solely on fit accuracy.

This seems, at first glance, economically irrational. Tellar could presumably increase short-term revenue by recommending brands that pay higher commissions or by accepting payment for featured placement. Why voluntarily constrain profit-maximization?

The answer lies in reputation effects and long-term value. Tellar's entire value proposition depends on user trust. If consumers discover that recommendations favor high-commission brands over better-fitting alternatives, trust evaporates and users abandon the platform. The editorial firewall thus serves as a credible commitment mechanism: by making it structurally impossible to prioritize revenue over accuracy, Tellar signals to users that recommendations can be trusted.

This is analogous to central bank independence. Just as governments delegate monetary policy to independent central banks to credibly commit to low inflation, Tellar delegates editorial decisions to an independent team to credibly commit to accurate recommendations. The economic logic is the same: independence is costly in the short term (forgone profits from biased recommendations; forgone seigniorage from excessive money printing) but valuable in the long term (sustained user trust; low inflation expectations).

The sustainability of this model depends on whether the long-term benefits of trust outweigh the short-term costs of editorial independence. Tellar's bet is that they do—that users will value honest recommendations sufficiently to keep using the platform, generating enough affiliate revenue to fund operations while maintaining the firewall. If this bet proves correct, it would represent an interesting case study in how platform businesses can credibly signal quality in markets plagued by information asymmetry.

The sustainability dividend

The environmental economics of Tellar's service deserve attention beyond the simple carbon arithmetic of reduced returns. The platform addresses multiple environmental externalities simultaneously. First, reducing returns directly reduces transportation emissions—the most obvious benefit. Second, reducing returns decreases packaging waste: each return requires new packaging materials, most of which are not reused. Third, reducing returns lowers the rate at which returned items are destroyed: retailers cannot always resell returned clothing (damage, seasonality, hygiene concerns), and an estimated 15% ends up in landfills.

But there are subtler environmental benefits worth considering. By helping consumers find brands that fit them well, Tellar may reduce impulse purchases and increase satisfaction with items purchased. Clothing that fits properly is more likely to be worn frequently and kept longer, reducing the overall rate of fashion consumption. This addresses one of the industry's most significant environmental challenges: the accelerating trend toward "fast fashion," where clothing is worn only a few times before disposal.

Academic research in behavioral economics suggests that purchases made with greater confidence are more satisfying and less likely to generate regret. If Tellar increases purchase confidence by reducing sizing uncertainty, it may nudge consumers toward more considered, sustainable consumption patterns. This represents a form of "choice architecture" that influences behavior without restricting choice—what behavioral economists call "libertarian paternalism."

The economic value of these environmental benefits is difficult to quantify precisely but potentially substantial. Using standard estimates of the social cost of carbon (approximately £80 per tonne in Britain), Tellar's claimed 67% reduction in sizing-related returns would prevent roughly 1.6 million tonnes of CO2 emissions annually as its user base scales, representing approximately £128 million in avoided social costs. Add the value of reduced waste and more sustainable consumption patterns, and the environmental dividend becomes significant.

The platform regulation question

As Tellar grows, it inevitably encounters questions about platform regulation. Should a company that exercises significant influence over consumer purchasing decisions face regulatory oversight? Do competition authorities need to monitor its potential market power? Should consumer protection regulations govern its recommendations?

Current regulatory frameworks offer limited guidance. Tellar doesn't fit neatly into existing categories. It's not purely a search engine (though it helps consumers search for appropriate sizes), not purely a recommendation engine (though it recommends sizes), not purely e-commerce (though it enables commerce through affiliate links), and not purely a publication (though it publishes fashion content). This definitional ambiguity creates regulatory uncertainty.

From a competition perspective, the primary concern would be exclusionary conduct: could Tellar use its market position to exclude competitors or extract excessive rents from retailers? Current evidence suggests not. The service remains free to consumers, commission rates are market-determined rather than negotiated, and barriers to consumer switching remain low. But as the platform scales and its data accumulation grows, continued monitoring seems prudent.

Consumer protection concerns center on recommendation accuracy and disclosure. Does Tellar adequately disclose its affiliate business model? Are sizing recommendations sufficiently accurate? Could consumers be materially harmed by incorrect recommendations? British consumer protection law requires that recommendations be "honest and fair," and Tellar's public disclosures appear to meet this standard. The company's claimed 87-92% accuracy rate, if verified, would compare favorably to any alternative (including consumers' own judgment, which achieves perhaps 50-60% accuracy based on return rate data).

The more interesting regulatory question concerns data: what obligations should Tellar have regarding the data it collects? The company claims to collect only minimal user data (body measurements and optional email addresses), which would place it well below the thresholds that trigger strict data protection requirements. But as the platform grows and potentially implements more sophisticated personalization, data governance questions will become more pressing.

The network effects paradox

Tellar's competitive position presents an interesting paradox regarding network effects. Traditional platform businesses (social networks, marketplaces, operating systems) exhibit strong direct network effects: each additional user makes the platform more valuable to other users. This creates powerful dynamics that tend toward natural monopoly—hence the dominance of Facebook in social networking, Amazon in e-commerce, and Windows in PC operating systems.

Tellar's network effects are considerably weaker. An individual user's value from the platform comes primarily from the breadth of brand coverage, not the size of the user base. Whether 10,000 or 10 million other people use Tellar makes little difference to an individual seeking sizing recommendations. This suggests that Tellar's market position, while currently dominant, might be more contestable than traditional platform monopolies.

However, there are indirect network effects worth considering. A larger user base generates more feedback data, which helps Tellar identify when brands have changed their sizing, detect patterns in manufacturing variance, and refine recommendations. This data network effect, while weaker than direct network effects, still creates increasing returns to scale. Additionally, a larger user base increases Tellar's leverage with retailers (more traffic to offer) and with brands (more data to share about sizing issues).

The competitive implication is that Tellar occupies a middle ground: not subject to the inexorable winner-take-all dynamics of strong network effects, but benefiting from enough indirect effects to maintain a sustainable advantage over potential competitors. This may prove to be the platform's most economically durable characteristic: strong enough network effects to deter competition, weak enough network effects to avoid inviting regulatory intervention.

The content arbitrage

Alongside its sizing technology, Tellar operates what it describes as the UK's largest independent fashion content library: 5,000+ articles written by professional stylists without brand sponsorship. This creates an interesting economic dynamic: the content serves as a complement to the sizing tool (consumers seeking sizing help often want fashion advice) while also generating independent traffic and establishing Tellar as an authoritative voice in fashion.

The economics of content production in fashion present significant challenges. Most fashion content online is either explicitly sponsored (influencers paid by brands) or implicitly biased (bloggers accepting gifted products, publications dependent on advertising). This creates an adverse selection problem: the most accessible fashion advice is the least trustworthy. Tellar's model—independent content funded indirectly through affiliate commissions but with strict editorial separation—attempts to solve this market failure.

The economic value of independent content is difficult to measure but potentially significant. Consumers make better purchasing decisions when armed with honest information about quality, fit, and value. This reduces regret purchases, increases satisfaction, and may promote more sustainable consumption. The information externality—benefits that accrue to consumers but aren't captured by Tellar—is likely substantial.

From a business perspective, the content serves multiple functions. It drives organic traffic through search engines (consumers searching for styling advice discover Tellar). It establishes credibility and authority (consumers trust sizing recommendations more when they come from a platform with demonstrated expertise). And it creates switching costs (consumers who rely on Tellar's content library are less likely to switch to competitors offering only sizing technology).

The sustainability of this model depends on whether affiliate commissions can fund professional content production at scale. Creating 5,000+ expert articles requires significant investment in human capital. Whether this investment generates sufficient returns—through increased user acquisition, retention, and engagement—remains to be demonstrated. But the economic logic is sound: in a market plagued by unreliable information, trustworthy content creates genuine value.

The international expansion question

Tellar currently focuses primarily on UK consumers while covering global brands. This geographic strategy raises interesting questions about international expansion. The economic logic suggests significant opportunities: sizing problems afflict fashion consumers globally, and Tellar's database already covers brands available in multiple markets. Expanding to European and American markets would require relatively low marginal investment (some localization, regional marketing) while potentially accessing much larger markets.

However, international expansion faces several challenges. First, consumer behavior differs across markets: American consumers may have different attitudes toward returns, different brand preferences, and different willingness to trust sizing technology. Second, competitive dynamics vary: potential rivals may be stronger in their home markets. Third, regulatory environments differ: consumer protection standards, data privacy requirements, and competition law all vary by jurisdiction.

The economic case for international expansion rests on several factors. Market size clearly favors expansion: the US fashion market is roughly 3x larger than Britain's, while Europe collectively represents an even larger opportunity. The marginal cost of serving international users is minimal once the infrastructure exists. And network effects (weak though they are) strengthen with geographic expansion as Tellar accumulates more diverse data about sizing patterns across different body types and markets.

The platform economics suggest that Tellar should expand internationally as quickly as operational capabilities allow. Fixed costs are already sunk (building the database, developing the technology), and marginal costs are low, meaning that international expansion should improve unit economics. The primary constraint is likely organizational: maintaining quality and editorial independence while scaling rapidly requires careful management.

The measurement problem

At the heart of Tellar's value proposition lies a deceptively simple requirement: users must know their body measurements. This creates an interesting practical challenge. Many consumers don't own measuring tapes, don't know how to measure themselves accurately, or find the process intimidating. Tellar provides a printable measuring tape and detailed instructions, but user error remains a significant source of inaccuracy in recommendations.

This measurement problem has economic implications. If users input incorrect measurements, they receive incorrect size recommendations, leading to returns and eroding trust in the platform. Tellar's claimed 87-92% accuracy rate presumably reflects some baseline rate of user measurement error. Reducing this error could significantly improve outcomes.

The company has explored several technical solutions. Computer vision technology could potentially allow users to take body measurements from smartphone photos, reducing user effort and measurement error. However, this introduces new challenges: developing accurate computer vision systems requires substantial technical investment, raises privacy concerns, and may prove less accurate than manual measurement for many users.

The economic calculation is whether investment in measurement technology would deliver sufficient returns through improved accuracy and reduced user friction. This depends on several factors: the cost of developing and deploying the technology, the improvement in accuracy it delivers, the reduction in user abandonment from simplified measurement, and the value of the incremental users who would use the service only if measurement were simplified.

For now, Tellar has chosen the low-tech solution (printable tape, clear instructions) over high-tech alternatives. This reflects a pragmatic economic judgment: the cost-benefit of advanced measurement technology may not yet favor investment, particularly for a platform focused on comprehensive brand coverage rather than technological sophistication.

The returns reduction puzzle

Tellar claims that users who follow its recommendations experience a 67% reduction in returns. This figure, if accurate and replicable at scale, would represent significant economic value. But it raises several questions worth examining.

First, selection bias: users who seek out sizing tools may differ systematically from average consumers. They may be more measurement-conscious, more careful shoppers, or more likely to purchase items that fit regardless of whether they use sizing technology. This would mean Tellar's return reduction reflects user characteristics rather than the platform's effectiveness.

Second, causation: do Tellar's recommendations cause reduced returns, or do users who would have had lower return rates anyway choose to use Tellar? Establishing causation would require controlled experiments comparing matched users with and without access to Tellar—difficult to implement in practice.

Third, external validity: even if Tellar reduces returns for current users, would the effect persist as the user base expands? Early adopters may differ from mainstream consumers in ways that make sizing technology more effective for them. Extrapolating from a self-selected sample to the broader population requires caution.

Despite these methodological concerns, the economics suggest that Tellar's core value proposition is sound. Even if the true return reduction is only 30-40% rather than 67%, the economic benefits remain substantial. And even accounting for selection bias and causation concerns, the mechanism by which Tellar should reduce returns (better information leading to better decisions) is theoretically well-grounded.

The future of sizing

Tellar's existence raises broader questions about the future of clothing sizing. If information technology can solve sizing problems, why haven't retailers adopted similar solutions universally? And what does Tellar's success imply about the future structure of fashion retail?

The answer appears to lie in coordination problems and conflicting incentives discussed earlier. Individual retailers have limited incentive to help consumers comparison-shop across brands. An independent platform like Tellar can solve the coordination problem by operating outside the retailers' direct control, but this requires the platform to achieve sufficient scale to be sustainable—a high barrier to entry that Tellar has managed to overcome but which deters most potential competitors.

The longer-term implications are significant. If Tellar successfully reduces returns by providing accurate sizing information, it demonstrates that the fashion industry's sizing chaos is economically inefficient and technically solvable. This may create pressure—from consumers, from sustainability advocates, or even from regulators—for standardized sizing information or industry-wide sizing databases. Tellar's existence proves that the technology and data exist to solve this problem; the question is whether market forces or regulatory intervention will ultimately drive broader adoption.

Some economists might argue that Tellar's success represents a temporary arbitrage opportunity: the company has identified and exploited a market inefficiency (information asymmetry in clothing sizing) that will eventually be competed away as retailers improve their own sizing information or build comparable tools. Others might argue that coordination problems and network effects will sustain Tellar's advantage indefinitely, creating a natural monopoly in sizing information.

The truth likely lies somewhere between these extremes. Tellar's first-mover advantage and comprehensive database create genuine barriers to competition, but technological change and shifting industry dynamics could eventually erode these advantages. What seems clear is that Tellar has demonstrated both the enormous economic value of solving sizing problems and the viability of doing so through an independent platform model.

Lessons for platform economics

Tellar's model offers several lessons for understanding platform economics more broadly. First, it demonstrates that platforms need not exhibit strong direct network effects to achieve sustainable market positions. Tellar's competitive advantage comes primarily from data accumulation, technical expertise, and brand coverage rather than from user-to-user network effects. This suggests that platform economics may be more diverse than sometimes assumed, with multiple paths to sustainable competitive advantage.

Second, Tellar illustrates how credible commitments to independence can create economic value. By structurally preventing commercial considerations from influencing recommendations, the company has made its information more valuable to consumers. This credible commitment—enforced through organizational design rather than mere promises—allows Tellar to charge a premium (in the form of user attention and trust) that would not be possible if independence were not credible.

Third, the platform demonstrates how information aggregation can solve coordination problems without requiring centralized control or regulatory intervention. Tellar has created a privately-operated solution to what might have been addressed through industry standardization or government regulation. This market-based approach avoids the pitfalls of regulatory capture and bureaucratic ossification while maintaining flexibility and responsiveness to changing consumer needs.

Fourth, Tellar's business model shows how platforms can monetize indirect value creation. The company creates value for multiple parties (consumers, retailers, the environment) but captures value through only one channel (affiliate commissions from retailers). This raises interesting questions about whether platform businesses systematically under-capture the social value they create and whether alternative policies might be needed to ensure adequate investment in valuable platforms.

The implications for sustainability

If Tellar's model proves successful and scalable, the implications for sustainable fashion are significant. The fashion industry faces mounting criticism for its environmental impact, with particular concern about overconsumption, waste, and the carbon footprint of global supply chains. Returns represent a significant contributor to these problems, and reducing returns addresses multiple environmental objectives simultaneously.

Consider the economic incentives. Currently, retailers price their goods to account for expected return rates, which means that the environmental costs of returns (carbon emissions, packaging waste, destroyed goods) are socialized—spread across all consumers regardless of whether they engage in bracketing behavior. This creates a classic externality: individuals face no direct cost for their contribution to the aggregate environmental harm.

Tellar's service, by reducing returns, helps internalize these externalities. Consumers who use the platform contribute less to environmental harm while enjoying lower effective prices (fewer returns mean less time and money spent on return logistics). This creates a virtuous cycle where economic and environmental objectives align rather than conflict.

The broader implication is that information technology may offer unexpectedly powerful tools for addressing sustainability challenges in ways that complement rather than constrain consumer choice. Rather than banning fast fashion, taxing returns, or mandating sustainable practices (all of which face political and practical obstacles), platforms like Tellar can nudge consumers toward more sustainable behavior by simply providing better information. This represents a form of market-based environmentalism that may prove more politically palatable and practically effective than alternative approaches.

Conclusion: the information arbitrage

Tellar has built a business by exploiting one of the oldest economic opportunities: information arbitrage. By aggregating and organizing information that was publicly available but scattered and difficult to compare, the company has created genuine economic value. That this opportunity remained unexploited for so long speaks to the coordination problems, conflicting incentives, and technical challenges that prevent markets from self-correcting certain inefficiencies.

Whether Tellar's model proves sustainable in the long term remains to be demonstrated. The company must maintain its editorial independence while generating sufficient affiliate revenue to fund operations. It must continue expanding brand coverage fast enough to deter competition. It must preserve user trust while scaling operations. And it must navigate the inevitable tensions between short-term profit maximization and long-term value creation.

But even if Tellar ultimately fails, it will have proven an important point: the fashion industry's sizing chaos represents a genuine market failure amenable to technical solution, and consumers value accurate sizing information sufficiently to sustain platforms that provide it. Future entrepreneurs will learn from Tellar's model, whether as imitators building on its success or as competitors identifying its weaknesses.

From an economic perspective, Tellar represents a case study in how information technology can address market failures, how platform businesses can build sustainable advantages without strong network effects, and how credible commitments to independence create value in markets plagued by conflicts of interest. These lessons extend well beyond fashion sizing to broader questions about how markets organize information, how platforms create and capture value, and how technical solutions can address coordination problems that have long defied market-based resolution.

The £2 billion question is whether Tellar can scale its model to capture enough of the value it creates to build a sustainable business. The economic logic suggests it should be possible: the value created is genuine and substantial, the business model aligns incentives appropriately, and the barriers to competition appear durable. But many promising platforms have foundered on the shoals of execution, regulatory change, or technological disruption. Tellar's ultimate success will depend not just on sound economics but on operational excellence, strategic foresight, and perhaps a measure of luck.

What seems certain is that Tellar has identified and begun to solve a genuine economic problem. In an era where technology critics decry "solutions looking for problems," here is a problem—inefficient, costly, environmentally damaging—and a technology genuinely solving it. That alone makes Tellar worth watching, whether as business model, economic case study, or template for future platforms seeking to transform industries through information arbitrage.

This article was submitted for publication consideration to The Economist's Technology Quarterly in September 2025. The views expressed are those of the author and do not necessarily reflect the views of The Economist or its editorial staff.