German Additional Criteria for Dominance under the GWB

1. Introduction

German competition law adopts a multi-factor approach to market dominance. Under § 18 GWB (Gesetz gegen Wettbewerbsbeschränkungen), dominance does not depend exclusively on market share. The assessment considers the undertaking's overall market position, including financial strength, access to data, access to procurement and sales markets, corporate links, entry barriers, network effects, switching costs, economies of scale, and the competitive constraints arising from other market participants.

This becomes particularly important in digital markets because a firm may exercise substantial competitive power even where its conventional market share does not, by itself, establish dominance. German law therefore contains specific criteria for multi-sided and network markets under § 18(3a) GWB, alongside the broader cross-market concept of paramount significance under § 19a GWB.

2. Statutory Framework

A. § 18(1) GWB — Basic dominance test

An undertaking is dominant where, on the relevant product and geographic market, it:

1. has no competitors;
2. is not exposed to substantial competition; or
3. has an overriding market position in relation to its competitors.

Thus, dominance is fundamentally a question of competitive constraints, rather than simply market share.

B. § 18(3) GWB — Additional criteria

The statute expressly requires consideration of factors including:

• market share;
• financial strength;
• access to competitively relevant data;
• access to procurement or sales markets;
• links with other undertakings;
• legal or factual barriers to market entry;
• actual and potential competition;
• ability of competitors to expand;
• countervailing buyer power. 

These are cumulative assessment factors, not necessarily independent requirements.

C. § 18(3a) GWB — Digital and network markets

For multi-sided markets and network markets, the assessment additionally recognizes factors such as:

• direct and indirect network effects;
• simultaneous use of multiple platforms (multi-homing);
• switching costs;
• economies of scale associated with network effects;
• access to competitively relevant data;
• importance of the platform for competition.

The purpose is to capture forms of market power that traditional price-based analysis may underestimate.

D. § 18(3b) GWB — Intermediary markets

Where an undertaking operates an intermediary platform, German law also recognizes the special competitive position created where the intermediary itself participates on one or more sides of the platform.

This is especially important for hybrid platforms, where a marketplace operator simultaneously acts as:

platform operator + intermediary + seller + advertiser + service provider.

The Amazon litigation is particularly important here.

3. What Are the "Additional Criteria"?

The central principle is that German law asks:

How effectively is the undertaking constrained by actual and potential competitors?

The additional criteria help answer this question.

4. Financial Strength

Financial strength can reinforce dominance because a financially powerful undertaking may:

• sustain losses for longer;
• finance aggressive expansion;
• acquire emerging competitors;
• invest heavily in infrastructure;
• subsidize one side of a platform;
• withstand competitive pressure;
• enter adjacent markets rapidly.

Financial resources therefore matter particularly where competition depends upon enormous investment.

Example

A cloud-computing company possessing enormous financial resources may subsidize AI services, GPUs, storage and APIs until smaller competitors cannot match the investment.

Financial strength does not automatically equal dominance. It becomes significant when combined with other structural advantages.

5. Access to Competitively Relevant Data

One of the most important modern German criteria is access to data.

Data may constitute a competitive advantage because it can improve:

• algorithms;
• recommendation systems;
• advertising;
• pricing;
• AI training;
• customer targeting;
• product development;
• fraud detection;
• demand forecasting.

The relevant question is not merely:

"Does the undertaking possess a lot of data?"

Rather:

Does its access to competitively relevant data strengthen its ability to compete in a manner that rivals cannot readily reproduce?

The Facebook litigation illustrates this principle.

6. Access to Procurement and Sales Markets

An undertaking may acquire market power by controlling access to important commercial channels.

This is particularly significant for:

• marketplaces;
• app stores;
• advertising platforms;
• payment networks;
• logistics systems;
• cloud platforms;
• digital intermediaries.

A platform can therefore possess substantial power even where it does not itself manufacture the underlying product.

7. Vertical and Corporate Interconnections

Vertical integration can strengthen market power where an undertaking controls several stages of the supply chain.

For example:

manufacturer → operating system → app store → payment system → advertising

may produce considerably greater competitive power than control over only one layer.

The concern is especially strong when the undertaking can use power in one market to reinforce its position in another.

8. Barriers to Entry

German dominance analysis considers both legal and factual barriers.

Examples include:

• high capital requirements;
• intellectual-property advantages;
• regulatory requirements;
• access to essential infrastructure;
• network effects;
• customer lock-in;
• proprietary data;
• switching costs;
• economies of scale;
• brand effects;
• ecosystem integration.

Digital markets can therefore become concentrated even where there are technically no legal barriers to entry.

9. Network Effects

Network effects are particularly important under the modern GWB.

A platform becomes more valuable as more users participate.

For example:

More users → more sellers → more products → more consumers → more sellers

This creates a self-reinforcing cycle.

The BGH has recognized that indirect network effects may increase and reinforce themselves as a platform grows.

Consequently, a competitor with a smaller user base may face a structural disadvantage even if its technology is comparable.

10. Multi-Homing

German law also considers whether users can use several competing platforms simultaneously.

Single-homing

A user uses only one platform.

This tends to strengthen the platform's market power.

Multi-homing

A user simultaneously uses several platforms.

This can constrain market power.

However, multi-homing is not necessarily decisive. The practical question is:

• how easy is switching?
• how costly is maintaining multiple accounts?
• do sellers have to duplicate inventories?
• can data be transferred?
• are customers equally reachable?
• does one platform remain indispensable?

The Amazon litigation demonstrates that the mere availability of alternative channels does not automatically eliminate substantial platform power.

11. Switching Costs and Lock-In

Switching costs may be:

Financial

Contract termination fees or migration costs.

Technical

Data migration, API incompatibility or system redevelopment.

Operational

Employees must learn a new system.

Network-related

Users remain on the platform because everyone else remains there.

Data-related

Users cannot easily transfer historical data or accumulated reputation.

The greater these costs, the weaker the competitive constraint from nominally available alternatives.

12. Economies of Scale

Large digital platforms may enjoy enormous economies of scale.

For example:

more users → more data → better service → more users

and:

more users → greater revenue → greater investment → better infrastructure → more users

This can produce a substantial structural advantage over smaller rivals.

13. Countervailing Buyer Power

German law also asks whether customers can discipline a powerful supplier.

Large buyers may possess bargaining power because they:

• purchase substantial volumes;
• can switch suppliers;
• can vertically integrate;
• can sponsor alternative suppliers;
• can negotiate favorable conditions.

But buyer power is ineffective where customers are economically dependent upon the platform.

For example, a small seller technically may be able to sell elsewhere but still depend upon Amazon for access to a large proportion of consumers.

14. The Importance of Overall Assessment

A crucial principle is:

No single factor necessarily establishes dominance.

The BGH has repeatedly emphasized a Gesamtbetrachtung—an overall assessment of the relevant circumstances. In Facebook, the BGH explained that dominance ordinarily results from the combination of several factors, none of which necessarily has to be decisive by itself.

This is particularly important for digital markets.

A company might have:

• 40% market share;
• enormous data advantages;
• strong network effects;
• substantial financial resources;
• high switching costs;
• access to key commercial channels.

Its market power may therefore be considerably greater than its 40% market share suggests.

15. Six Important German Case Laws

1. BGH — Facebook, KVR 69/19, 23 June 2020

Facts

The Bundeskartellamt challenged Facebook's conditions requiring users to permit extensive combination of data generated on Facebook with data obtained from outside Facebook.

Importance for dominance

The BGH accepted Facebook's dominant position on the German social-network market following an overall assessment.

The Court emphasized:

• market position;
• network effects;
• the structure of a two-sided platform;
• competitive conditions on both sides;
• the importance of data;
• the absence of effective alternatives.

The Court held that dominance in a two-sided platform market must be assessed with regard to the particular characteristics of that market.

Principle

Dominance in digital markets is a structural and multi-factor inquiry rather than a simple market-share calculation.

16. BGH — Amazon, KVB 56/22, 23 April 2024

This is one of the most important modern authorities on the additional criteria.

The BGH upheld the Bundeskartellamt's finding that Amazon possessed paramount significance for competition across markets under § 19a GWB.

The Court also confirmed Amazon's dominance in the market for online marketplace services for commercial sellers under § 18 GWB, applying § 18(3), § 18(3a) and § 18(3b).

The Court emphasized:

• Amazon's marketplace position;
• network effects;
• hybrid structure;
• financial and resource advantages;
• data access;
• vertical integration;
• importance for third-party access to markets;
• ability to influence business activities of third parties.

The BGH stated that an undertaking may possess paramount cross-market importance where size and resource advantages and strategic positioning allow it to exert substantial influence over third parties or expand into new markets and sectors.

Principle

Platform power can derive from an ecosystem of mutually reinforcing advantages rather than dominance in only one market.

17. BGH — Apple, KVB 61/23, 18 March 2025

The BGH upheld the determination concerning Apple's paramount significance for competition across markets.

The case is important because it illustrates how the § 19a assessment can operate where a company possesses:

• a powerful ecosystem;
• control over important digital interfaces;
• extensive resources;
• strong integration across products and services;
• strategically important platform infrastructure.

The Court emphasized that § 19a addresses the special competitive risks created by undertakings operating on multi-sided and network markets.

Principle

Ecosystem control may create competitive power extending beyond the market in which conventional dominance is first established.

18. Bundeskartellamt — Meta/Facebook, § 19a GWB

The Bundeskartellamt determined that Meta possessed paramount significance for competition across markets.

The assessment considered factors such as:

• its dominant social-network position;
• extensive user base;
• financial strength;
• data resources;
• interconnected digital services;
• ecosystem effects.

The authority's approach illustrates how the traditional § 18 criteria can be supplemented by the broader § 19a assessment.

The Bundeskartellamt describes § 19a as a two-stage system: first, the authority determines whether the undertaking possesses paramount cross-market significance; second, it may prohibit specified forms of anti-competitive conduct.

19. Bundeskartellamt — Alphabet/Google, § 19a GWB

Google's position was assessed through its interconnected activities in:

• search;
• advertising;
• operating systems;
• browsers;
• mapping;
• video;
• cloud and other digital services.

The case demonstrates why vertical integration and activity across related markets are expressly relevant under § 19a.

Google's importance cannot necessarily be assessed by examining search alone because its ecosystem can produce advantages across multiple markets.

The Bundeskartellamt identifies Google, Meta, Amazon, Apple and Microsoft among the major undertakings for which § 19a proceedings or determinations have been undertaken.

20. Bundeskartellamt — Amazon Marketplace, § 19 GWB / § 19a GWB

Amazon's marketplace proceedings are particularly relevant to the access-to-markets criterion.

The Bundeskartellamt identified Amazon as a critical intermediary between:

• sellers and consumers;
• advertisers and consumers;
• logistics providers and sellers;
• manufacturers and retailers.

Amazon's platform therefore gives it substantial rule-setting capacity affecting third-party businesses.

The BGH subsequently confirmed that Amazon's marketplace position constituted dominance under § 18(1) together with § 18(3), § 18(3a) and § 18(3b).

Principle

Control over access to customers can itself become a major source of market power.

21. Relationship Between § 18 and § 19a GWB

A useful distinction is:

Section 19a expressly requires consideration of:

1. dominance on one or more markets;
2. financial strength/resources;
3. vertical integration and related markets;
4. access to competitively relevant data;
5. significance for third-party access to procurement and sales markets and influence over third parties. 

Thus, § 19a does not replace § 18 dominance analysis. It adds a special regime for undertakings whose power extends across markets.

22. Why the German Model Is Important

The German approach is particularly significant because it recognizes that modern market power may arise from a combination of:

Market share + data + network effects + financial strength + ecosystem integration + access control + switching costs + strategic positioning

rather than from market share alone.

For example:

A platform with 45% market share + enormous data + strong network effects + high switching costs + control of customer access may be more competitively powerful than a conventional firm with 65% market share but easily replaceable infrastructure.

This is one reason German competition law has become particularly influential in digital-platform regulation.

23. Practical Legal Test

A German competition authority examining dominance can therefore proceed approximately as follows:

Relevant Market

↓

Market Share

↓

Financial Strength

↓

Data Access

↓

Procurement/Sales Access

↓

Vertical & Corporate Links

↓

Entry Barriers

↓

Network Effects

↓

Multi-Homing

↓

Switching Costs / Lock-In

↓

Economies of Scale

↓

Actual & Potential Competition

↓

Countervailing Buyer Power

↓

Overall Assessment (Gesamtbetrachtung)

↓

Dominance under § 18 GWB

↓

Where the undertaking operates across multiple interconnected markets:

Additional § 19a GWB assessment

24. Conclusion

The additional criteria for dominance under the German GWB reflect a shift from a purely market-share-oriented conception of power toward a structural, ecosystem and capability-based analysis.

The most important principles are:

1. Market share is important but not conclusive.
2. Financial resources can reinforce market power.
3. Access to competitively relevant data is expressly recognized.
4. Control over procurement and sales channels can create strategic power.
5. Network effects can produce self-reinforcing dominance.
6. Switching costs and lock-in can weaken competitive constraints.
7. Multi-homing can constrain power but does not automatically eliminate dominance.
8. Vertical integration can extend power into related markets.
9. Countervailing buyer power must be examined.
10. Digital dominance requires a particularly careful analysis of platform structure.
11. § 19a GWB adds a cross-market dimension for undertakings of paramount significance.
12. The decisive methodology is an overall assessment (Gesamtbetrachtung) of all relevant competitive conditions.

The Facebook and Amazon decisions are especially important because they demonstrate that German law can recognize market power arising from data, network effects, platform intermediation, ecosystem integration and strategic access to third-party markets, even where conventional price-based indicators provide an incomplete picture.