Competition Law and Competition Implications of Reputation Economies

1. Introduction

Reputation economies are markets in which the reputation of a firm, seller, product, professional, platform, or service provider has substantial economic value and directly affects consumer choice, market access, pricing power, and competitive conditions.

In traditional markets, reputation was developed through advertising, repeated transactions, brand recognition, personal recommendations, and professional credentials. In digital markets, reputation is increasingly measured, stored, ranked, and distributed through ratings, reviews, seller scores, rankings, badges, recommendations, trust scores, verification systems, and platform algorithms.

Online reputation systems reduce information asymmetry because consumers often cannot directly observe the quality of a seller before purchasing. At the same time, reputation can become a competitive asset and, in some circumstances, a barrier to entry. Research describes reputation and feedback systems as mechanisms that facilitate trust and trade in marketplaces such as eBay, Airbnb, Uber and other platforms. (Annual Reviews)

From a competition-law perspective, the central question is not whether a company has a strong reputation. A strong reputation normally results from legitimate competition. The concern arises when reputation becomes connected with exclusionary conduct, manipulation, self-preferencing, discrimination, tying, foreclosure, misleading reviews, restrictions on portability, or control over a reputation infrastructure that rivals need to compete.

2. Meaning of Reputation Economies

A reputation economy exists where:

Economic value is substantially influenced by accumulated information about the past performance, reliability, quality or trustworthiness of a market participant.

Examples include:

Amazon seller ratings

Airbnb host ratings

Uber driver and passenger ratings

Google business ratings

Yelp reviews

TripAdvisor ratings

professional ratings

app-store ratings

financial or credit reputations

freelancer ratings

marketplace seller scores

restaurant ratings

hotel ratings

platform trust badges

verified-seller status.

The reputation may be generated by:

Consumers

Platforms

Independent reviewers

Professional associations

Algorithms

Transaction histories

Ratings and reviews

Repeat purchases

Complaint histories

Verification systems.

3. Economic Importance of Reputation

Reputation performs several economic functions.

A. Reducing information asymmetry

Consumers frequently cannot determine quality before purchase.

A reputation system provides information concerning previous transactions.

For example:

Unknown seller → reviews → consumer confidence → purchase

Thus, reputation can reduce search and information costs.

B. Building trust

Reputation allows strangers to transact.

This is particularly important in:

Airbnb

Uber

online marketplaces

freelance platforms

peer-to-peer platforms.

C. Rewarding quality

A seller with consistently positive reviews may attract more customers.

This can encourage:

better service

faster delivery

higher product quality

better customer support.

D. Creating economic value

Reputation can directly affect demand and revenue. Research concerning Yelp found a significant relationship between ratings and restaurant revenue, demonstrating that online reputation can have measurable commercial effects. (Google Books)

E. Creating switching costs

A consumer or seller may accumulate valuable reputation history on one platform.

Moving to another platform can mean losing:

reviews

ratings

transaction history

verified status

followers

customer trust.

Consequently, reputation can create platform-specific switching costs.

4. Reputation as a Competitive Advantage

A good reputation is normally a legitimate competitive advantage.

Competition law does not ordinarily require a successful firm to surrender advantages created through:

quality,

innovation,

service,

reliability,

investment,

brand building.

The problem arises where reputation is acquired or maintained through anticompetitive methods.

For example:

Firm A has 4.9/5 ratings because customers genuinely prefer its service.

This is generally competition on the merits.

But:

Firm A controls the marketplace and systematically removes competitors' negative reviews while promoting its own reputation.

This raises substantially different competition concerns.

5. Reputation Economies and Market Power

Reputation becomes particularly significant when combined with network effects.

Consider:

More sellers → more transactions → more reviews → better information → more consumers → more sellers

This creates a reinforcing cycle.

A large platform may therefore accumulate an enormous reputation-information advantage.

The resulting structure can resemble:

Users → transactions → reviews → reputation data → better matching → more users → more transactions

The accumulated data may make entry difficult for new competitors.

However, market size or popularity alone does not establish competition-law market power. The OECD has emphasized that being a large or economically powerful digital company is not automatically equivalent to possessing market power in the competition-law sense. (OECD)

6. Competition Concerns Created by Reputation Economies

A. Reputation-based barriers to entry

An established platform may possess years of:

reviews,

ratings,

customer feedback,

seller histories.

A new platform starts with little or no reputation information.

This creates a reputation-data disadvantage.

New entrants may therefore have difficulty attracting users even if they offer better prices or technology.

B. Reputation lock-in

Suppose a seller has:

20,000 positive reviews on Platform A.

Moving to Platform B may mean starting from zero.

The seller therefore has an incentive to remain with Platform A.

If a dominant platform deliberately prevents reputation portability, this could strengthen switching costs and potentially contribute to foreclosure concerns.

C. Review manipulation

Businesses may attempt to manufacture reputation through:

fake reviews,

paid reviews,

incentivised reviews,

review farms,

suppression of negative reviews,

manipulation of ratings,

competitor sabotage.

The CMA's work concerning Amazon and Google illustrates the regulatory importance of fake reviews and manipulation of online reputation systems. The CMA secured undertakings from both companies concerning systems for detecting and preventing fake or misleading reviews. (GOV.UK)

Although such proceedings primarily involve consumer protection, the conduct can also have competition implications where manipulated reputation changes competitive conditions between sellers.

7. Self-Preferencing and Reputation

A platform can potentially influence the reputation of businesses operating on it.

For example, a platform may control:

rankings,

search results,

badges,

verified status,

review visibility,

recommendation systems.

If the platform also operates its own competing business, it may have an incentive to give its own products or services preferential treatment.

This creates a competition-law issue similar to the concerns examined in Google Shopping.

8. Data Advantages and Reputation Economies

Reputation systems generate valuable datasets.

A platform can learn:

consumer preferences,

seller reliability,

conversion rates,

customer complaints,

product quality,

transaction frequency,

consumer behaviour.

This creates a potential data-based competitive advantage.

A dominant platform may therefore possess both:

Reputation capital; and

Reputation data.

The combination can strengthen market power.

9. Network Effects

Reputation systems frequently exhibit network effects.

Direct network effect

More users generate more ratings.

Indirect network effect

More consumers attract more sellers, while more sellers attract more consumers.

Data network effect

More transactions produce more data, allowing the platform to improve rankings and recommendations.

This can create a cycle:

Scale → Data → Better reputation information → More users → More scale

Such effects can make entry difficult even where a new entrant has superior technology.

10. Reputation and Abuse of Dominance

Where a firm is dominant, competition authorities may examine whether reputation-related conduct amounts to abuse.

Possible theories include:

1. Discriminatory treatment

A platform may give favourable reputation treatment to some businesses while disadvantaging rivals.

2. Self-preferencing

The platform may favour its own products in rankings.

3. Exclusionary ranking

Rivals may be systematically pushed down.

4. Refusal to provide access

A platform may deny competitors access to essential reputation information where the legal requirements for intervention are satisfied.

5. Data foreclosure

A dominant firm may restrict competitors from obtaining or transferring reputation-related data.

6. Loyalty mechanisms

A platform may use reputation-linked benefits to make sellers dependent on its ecosystem.

11. Reputation Economies and Consumer Welfare

Competition law ultimately examines competitive conditions and consumer welfare according to the applicable legal framework.

Authentic reputation systems can produce significant benefits:

better information,

lower search costs,

improved quality,

greater trust,

stronger competition based on service.

But unreliable systems can produce the opposite effects.

Research on fake reviews identifies two important mechanisms: misinformation about products and reduced trust in the review system itself. (National Bureau of Economic Research)

Thus:

Reliable reputation → better competition

whereas:

Manipulated reputation → distorted competition

12. Reputation Manipulation as a Competitive Strategy

A business may attempt to improve its position by:

Positive manipulation

Generating artificial positive reviews.

Negative manipulation

Generating negative reviews against competitors.

Review suppression

Preventing dissatisfied consumers from posting negative reviews.

Selective publication

Displaying favourable reviews while hiding unfavourable ones.

Algorithmic manipulation

Changing ranking systems to favour particular sellers.

These practices can distort the competitive process because consumers may make purchasing decisions on false information.

13. Six Major Case Laws and Their Relevance

The following cases are important because some directly concern digital reputation/review systems while others establish broader competition principles that can be applied to reputation economies.

Case 1: Google Shopping – European Commission v Google

Case: Google Search (Shopping), European Commission Decision, 27 June 2017; General Court, Case T-612/17.

Facts

Google was found to have given prominent placement to its own comparison-shopping service in search results while competing comparison-shopping services were disadvantaged.

The European Commission imposed a substantial fine under Article 102 TFEU.

The General Court subsequently upheld the essential finding concerning Google's conduct.

Competition-law principle

A dominant platform controlling an important gateway cannot necessarily use that position to systematically favour its own competing service.

Relevance to reputation economies

Reputation systems frequently involve:

rankings,

visibility,

recommendations,

search placement,

badges.

If a dominant platform controls the reputation architecture and simultaneously competes with businesses using that architecture, self-preferencing can become an important competition concern.

The case demonstrates that control over visibility can affect competitive opportunities. (ScienceDirect)

Case 2: FTC v Amazon.com

Case: Federal Trade Commission v Amazon.com, Inc., U.S. federal antitrust litigation, filed 2023.

Facts

The FTC and state plaintiffs alleged that Amazon engaged in various exclusionary practices affecting online retail competition.

The case concerns Amazon's extensive marketplace ecosystem, where sellers depend on:

search visibility,

marketplace access,

consumer ratings,

seller reputation,

fulfilment systems.

Competition-law significance

The case illustrates how a major marketplace can potentially influence competitive conditions through control over an ecosystem rather than through conventional ownership of all participating businesses.

Relevance to reputation economies

Amazon operates a major reputation infrastructure consisting of:

seller ratings,

product reviews,

rankings,

fulfilment-related signals,

customer feedback.

A competition analysis may therefore need to consider whether platform rules affecting reputation and visibility advantage the platform's own interests or disadvantage competing sellers.

Case 3: FTC v Qualcomm Inc.

Case: Federal Trade Commission v Qualcomm Inc., 969 F.3d 974 (9th Cir. 2020).

Facts

The FTC challenged Qualcomm's licensing practices and alleged exclusionary conduct involving modem chip markets.

The Ninth Circuit ultimately reversed the district court's judgment against Qualcomm.

Competition-law principle

Competition law distinguishes between:

possessing a valuable competitive advantage; and

unlawfully obtaining or maintaining market power through exclusionary conduct.

Relevance to reputation economies

The same distinction applies to reputation.

A company may legitimately have:

superior reputation + loyal customers + strong brand.

Competition law does not automatically condemn this.

The legal question is whether the competitive advantage is associated with conduct that unlawfully excludes competitors.

Case 4: Aspen Skiing Co. v Aspen Highlands Skiing Corp.

Case: 472 U.S. 585 (1985).

Facts

Several ski operators historically participated in a cooperative ticket arrangement.

Aspen Skiing later withdrew from the arrangement with Aspen Highlands, despite the previous cooperation.

The U.S. Supreme Court treated the conduct as potentially unlawful exclusionary conduct under Section 2 of the Sherman Act.

Competition-law principle

Under specific circumstances, a dominant firm's termination of a profitable course of dealing can raise exclusionary-conduct concerns.

Relevance to reputation economies

Suppose a dominant marketplace previously permitted sellers to:

export ratings,

maintain reputation histories,

participate in reputation-sharing mechanisms.

A sudden exclusionary withdrawal could potentially become relevant under refusal-to-deal or related doctrines, depending on the jurisdiction and facts.

The case does not establish that reputation data is automatically an essential facility. Rather, it provides a framework for analysing certain forms of exclusionary conduct.

Case 5: United States v Microsoft Corp.

Case: 253 F.3d 34 (D.C. Cir. 2001).

Facts

Microsoft was found liable for several exclusionary practices involving the Windows operating-system platform and competing technologies, particularly Netscape's browser.

Competition-law principle

A dominant platform can unlawfully maintain its position when it uses platform control to disadvantage competing products.

Relevance to reputation economies

Digital reputation platforms similarly possess an important gateway:

Platform → ranking → consumer attention → seller sales

Where the platform controls access to consumers and reputation signals, its rules can affect the competitive process.

The Microsoft case is therefore useful for understanding platform leverage and exclusionary conduct, even though it did not concern online ratings.

Case 6: Booking.com and European Commission / National Competition Authority Proceedings Concerning Hotel Distribution

Case: Booking.com-related competition proceedings concerning most-favoured-nation clauses and hotel-platform relationships.

Facts

Booking platforms have historically used contractual mechanisms affecting the prices and conditions hotels offer through other distribution channels.

Competition authorities in Europe examined various forms of parity/MFN clauses.

Competition-law significance

The cases demonstrate that platform contracts can influence:

market access,

price competition,

multi-homing,

dependence on platforms.

Relevance to reputation economies

A platform can possess several forms of competitive leverage simultaneously:

customer access + reputation + ranking + transaction data + contractual restrictions

Therefore, reputation should not be analysed in isolation.

A platform's reputation infrastructure can make contractual restrictions substantially more significant because sellers may be reluctant to leave a platform where they have accumulated extensive ratings and customer trust.

Case 7: Kimzey v Yelp!

Case: Kimzey v Yelp!, Inc., 836 F.3d 1263 (9th Cir. 2016).

Facts

A locksmith business challenged Yelp over review-related conduct and Yelp's rating system.

The Ninth Circuit held that Yelp's aggregation of user-generated ratings into a star-rating system constituted user-generated information for purposes relevant to the litigation and rejected the plaintiff's attempt to impose liability on Yelp under the asserted theory.

Relevance

The case is particularly useful for understanding the legal significance of:

ratings,

aggregated reputation scores,

user-generated reviews,

platform reputation systems.

The case itself is primarily a Section 230 matter rather than an antitrust decision, but it demonstrates how the technical design of reputation systems can have important legal consequences. (Justia Law)

14. Case Law Comparison

15. Reputation Portability

One of the most important emerging competition issues is reputation portability.

Imagine:

Seller has 10,000 five-star reviews on Platform A.

If Platform A prevents the seller from transferring those reviews to another platform, the seller faces a significant switching cost.

This may discourage:

multi-homing,

entry,

platform switching,

competition between platforms.

However, mandatory portability raises countervailing issues such as:

privacy,

authenticity,

data ownership,

fraud,

contextual differences,

verification.

Therefore, competition authorities must balance contestability against the integrity of the reputation system.

16. Reputation Data as a Strategic Asset

Reputation data can contain:

transaction history,

customer reviews,

ratings,

complaints,

seller performance,

delivery records,

cancellation rates,

response rates.

This data can improve:

search algorithms,

recommendations,

fraud detection,

matching,

advertising,

credit decisions.

Consequently, a dominant platform's control over reputation data may create an important competitive advantage.

17. Algorithmic Reputation Systems

Modern reputation systems increasingly rely on algorithms.

An algorithm may determine:

which reviews appear first,

which seller receives a badge,

which business appears in search,

which seller receives recommendations,

which reviews are removed,

which seller receives higher visibility.

This introduces the possibility of algorithmic discrimination.

For example:

Seller A and Seller B have similar ratings, but the algorithm systematically gives Seller A greater visibility because Seller A participates in the platform's preferred ecosystem.

Such conduct may require competition-law examination where it materially disadvantages rivals.

18. Reputation and Self-Preferencing

A vertically integrated platform can occupy two positions:

Platform operator

and

Competitor of marketplace participants

This creates a conflict of incentives.

The platform controls:

reputation,

rankings,

customer information,

search,

recommendations.

At the same time, it may sell its own products.

This creates potential self-preferencing concerns similar to those discussed in Google Shopping.

19. Reputation and Tying

A platform might require businesses to use its reputation system as a condition of obtaining another service.

For example:

Seller must use Platform A's payment, delivery, advertising and reputation services to obtain meaningful marketplace visibility.

If the firm possesses sufficient market power and the legal requirements for tying are satisfied, such arrangements can attract competition-law scrutiny.

20. Reputation and Exclusive Dealing

A dominant platform could theoretically offer:

"Maintain your premium reputation badge only if you sell exclusively through our platform."

This could discourage sellers from using rival platforms.

The reputation benefit then becomes a mechanism for foreclosure.

The competitive concern is not the existence of the badge itself but whether its use creates unlawful exclusionary effects.

21. Reputation and Predatory Reputation Attacks

Competition problems may arise not only from a dominant platform but also from competing businesses.

Competitors may:

create fake negative reviews,

report false complaints,

manipulate ratings,

coordinate review attacks.

Such behaviour can distort competition.

The harm can be especially serious where consumers heavily rely on ratings.

22. Reputation and Mergers

Reputation economies are relevant to merger analysis.

Suppose:

Platform A + Platform B

results in concentration of:

consumer reviews,

seller ratings,

transaction histories,

recommendation data.

The merger may eliminate an important source of competitive pressure.

Authorities may therefore consider whether the transaction creates:

data concentration,

network effects,

increased switching costs,

reduced multi-homing,

reduced innovation,

increased dependence on one reputation infrastructure.

23. Reputation and Innovation

Competition between reputation systems can itself promote innovation.

Different platforms may compete through:

better fraud detection,

better review verification,

improved ranking systems,

more accurate ratings,

transparent algorithms,

better consumer protection.

If one dominant system becomes unavoidable, incentives to innovate reputation technology may decrease.

24. Reputation and Consumer Choice

A healthy reputation economy can improve consumer choice by allowing consumers to compare:

quality,

price,

reliability,

service,

delivery,

customer satisfaction.

But manipulation can create false choice.

For example:

A consumer sees:

Seller A — 4.9 stars

and

Seller B — 3.8 stars.

If Seller A's rating was artificially generated, the competitive decision is distorted.

25. Reputation and Small Businesses

Reputation systems can have both pro-competitive and exclusionary effects for small businesses.

Potential benefits

Small businesses can compete against established brands by demonstrating:

superior service,

quality,

customer satisfaction.

Potential disadvantages

A new small business has:

fewer reviews,

lower visibility,

limited historical data,

lower algorithmic trust.

Therefore, reputation systems can simultaneously reduce traditional brand barriers and create new digital reputation barriers.

26. Reputation Economies and Multi-Homing

Multi-homing means participating in multiple platforms.

Example:

Restaurant → Google + Yelp + TripAdvisor

Multi-homing reduces dependence on one platform.

However, if reputation is not portable, businesses may prefer to remain on the platform where they have accumulated the strongest reputation.

This can strengthen platform market power.

27. Reputation and Interoperability

Interoperability can potentially reduce switching costs.

Possible mechanisms include:

reputation portability,

common verification standards,

interoperable seller identities,

transferable transaction records.

But interoperability can also create risks of:

fake reviews,

identity fraud,

privacy violations,

manipulation.

Competition policy therefore needs to distinguish between legitimate technical restrictions and restrictions designed to prevent competitive entry.

28. Reputation Economies and Digital Markets

Digital markets are particularly susceptible to reputation-based concentration because they combine:

Data

Algorithms

Network effects

User-generated content

Switching costs

Economies of scale.

The result may be a self-reinforcing reputation ecosystem:

More users
↓
More transactions
↓
More reviews
↓
Better reputation information
↓
Greater consumer trust
↓
More users

This is economically efficient when reputation information is genuine.

It becomes problematic where the cycle is maintained through exclusionary conduct.

29. Consumer Protection and Competition Law Overlap

Reputation problems often fall simultaneously within:

Consumer law

Fake or misleading reviews.

Competition law

Exclusionary conduct and market foreclosure.

Contract law

Terms restricting reviews or portability.

Data protection law

Processing and transfer of reputation information.

Defamation law

False statements affecting reputation.

Thus, the same conduct may have multiple legal dimensions.

The CMA's continuing work concerning fake online reviews demonstrates the close relationship between reputation integrity and consumer protection. (GOV.UK)

30. Economic Effects of Fake Reviews

Fake reviews can produce:

Allocative inefficiency

Consumers buy products that do not match their preferences.

Competitive distortion

Honest businesses lose customers.

Entry barriers

New competitors may be unable to obtain credible reputation.

Reduced trust

Consumers become less confident in the entire rating system.

Market concentration

Businesses capable of manipulating reputation may gain market share.

Recent economic research on Amazon identifies both misinformation and loss of trust as mechanisms through which fake reviews can reduce consumer welfare and shift sales toward dishonest sellers. (National Bureau of Economic Research)

31. Competition Law Tests for Reputation-Based Conduct

A competition authority would generally need to examine several questions.

Question 1: What is the relevant market?

Possible markets include:

online marketplace services,

review services,

search services,

hotel booking,

restaurant discovery,

digital advertising.

Question 2: Does the undertaking possess market power?

Indicators may include:

market share,

network effects,

switching costs,

entry barriers,

data advantages,

consumer dependence.

Question 3: What is the conduct?

Examples:

self-preferencing,

exclusivity,

tying,

discriminatory treatment,

refusal to deal,

manipulation,

data restrictions.

Question 4: Does the conduct harm competition?

Authorities may examine:

foreclosure,

reduced entry,

reduced innovation,

reduced consumer choice,

increased switching costs.

Question 5: Are there efficiencies?

A reputation restriction might sometimes be justified by:

fraud prevention,

privacy,

security,

authenticity,

quality control.

Therefore, not every restriction involving reputation is automatically unlawful.

32. Legitimate Reputation vs Anticompetitive Reputation

The crucial distinction is competition on the merits versus exclusionary conduct.

33. Regulatory Approaches

Competition authorities and regulators can consider several approaches.

A. Transparency

Platforms should explain significant reputation criteria.

B. Review verification

Platforms can develop mechanisms to detect:

fake reviews,

paid reviews,

coordinated manipulation.

C. Data portability

Where legally and technically appropriate, portability can reduce switching costs.

D. Non-discrimination

Dominant platforms may need to avoid unjustified discriminatory treatment of competing sellers.

E. Algorithmic accountability

Important ranking decisions may require appropriate oversight.

F. Consumer protection

False or misleading reputation information should be addressed.

34. Important Limitations

Competition law should not treat every successful reputation system as anticompetitive.

A reputation system can produce substantial efficiencies.

For example:

More accurate ratings → better consumer decisions → greater competition based on quality.

Similarly, a dominant firm's strong reputation may simply result from:

superior quality,

innovation,

reliability,

investment.

Competition law generally becomes concerned when market power is maintained or extended through unlawful exclusionary conduct, rather than merely because consumers prefer a well-regarded company.

The OECD similarly cautions that economic power or large size does not automatically establish competition-law market power. (OECD)

35. Emerging Issues

Reputation economies are evolving rapidly.

Important future issues include:

1. AI-generated reviews

Generative AI can produce thousands of realistic reviews.

2. AI reputation scores

Algorithms may automatically calculate trustworthiness.

3. Decentralised reputation

Blockchain systems may allow portable reputation records.

4. Cross-platform reputation

A single identity may carry ratings between marketplaces.

5. Reputation scoring of workers

Gig workers may be heavily dependent on platform ratings.

6. Automated de-platforming

Algorithms may suspend sellers based on reputation signals.

7. Reputation manipulation by AI

Bots can create artificial positive or negative reviews at scale.

8. Synthetic identities

Artificial accounts may create apparently independent reputation signals.

36. Overall Legal Analysis

The competition implications of reputation economies can be summarised through five major concepts:

First, reputation is an economic asset.

Second, reputation systems reduce information asymmetry and facilitate transactions.

Third, accumulated reputation can create switching costs and entry barriers.

Fourth, dominant platforms may possess substantial competitive power because they control reputation infrastructure, rankings and associated data.

Fifth, competition law becomes particularly relevant where reputation is manipulated or used as a mechanism for exclusion, self-preferencing, discriminatory treatment, tying, exclusivity or foreclosure.

The distinction between reputation earned through competition and reputation protected through exclusionary conduct is therefore central.

37. Exam-Oriented Conclusion

Reputation economies represent an important development in modern competition law, especially in digital markets. Reputation, ratings, reviews and trust scores reduce information asymmetry and can promote quality competition. At the same time, accumulated reputation can create network effects, switching costs, data advantages and barriers to entry.

Competition concerns arise when firms manipulate reputation systems, restrict reputation portability, suppress negative information, favour their own services, discriminate against competitors or use reputation-related advantages to exclude rivals. The principles developed in cases such as Google Shopping, FTC v Amazon, FTC v Qualcomm, Aspen Skiing, United States v Microsoft, Booking.com proceedings and Kimzey v Yelp! provide useful frameworks for analysing these issues, although not all of these cases directly concern reputation economies.

The fundamental competition-law question is therefore:

Whether reputation represents a legitimate competitive advantage earned through superior performance, or whether control over reputation has been used as a mechanism to distort or exclude competition.

Recent regulatory attention to fake reviews by platforms such as Amazon and Google demonstrates the increasing economic and legal importance of trustworthy reputation systems. (GOV.UK)

Quick Revision Points

Reputation is an important intangible economic asset.

Reputation systems reduce information asymmetry.

Ratings can influence consumer demand and business revenue.

Reputation can create network effects and switching costs.

Reputation data can become a strategic competitive asset.

Fake reviews can distort competition.

Reputation suppression can disadvantage rivals.

Self-preferencing can affect reputation and visibility.

Non-portable reputation can create platform lock-in.

Dominant platforms require particular scrutiny where reputation infrastructure is used to exclude competitors.

Google Shopping is relevant to ranking and self-preferencing.

Aspen Skiing is relevant to certain exclusionary refusal-to-deal situations.

Microsoft is relevant to platform leveraging.

Kimzey v Yelp! illustrates the legal significance of aggregated rating systems.

The key distinction is between competition on the merits and exclusionary manipulation of reputation.