Civil Law and Ad-Tech Stack Vertical Integration Conflicts in Europe

1. Meaning

Ad-tech stack vertical integration means that one corporate group operates at several successive levels of the digital advertising chain.

A simplified ad-tech chain is:

Advertiser → DSP → Ad Exchange → SSP → Publisher Ad Server → Publisher

A vertically integrated group may control several of these layers simultaneously. For example, the same group may operate an advertiser-side buying platform, an exchange, and publisher-side technology.

The legal conflict arises when the integrated undertaking allegedly uses its position at one level to advantage its own service at another level—for example, by preferential ranking, discriminatory access, manipulation of auction rules, discriminatory fees, use of commercially sensitive information, or self-preferencing.

The European Commission's 2025 Google ad-tech decision is particularly important: under Article 102 TFEU, the Commission found that Google's practices favoured its own online-display advertising technology services and imposed a €2.95 billion fine. The Commission's published decision specifically discusses the structural risks created by Google's vertical integration across the ad-tech stack. (Competition Case Search)

Important: this is a relatively new application of established European competition-law principles. There are not yet six final CJEU judgments specifically concerning ad-tech-stack vertical integration. Therefore, the cases below combine the direct ad-tech authority with established CJEU authorities on self-preferencing, vertical foreclosure, margin squeeze, information advantages and abuse of dominance.

2. Main European Legal Framework

The principal legal provisions are:

Article 101 TFEU

Deals with anti-competitive agreements and coordinated conduct.

It becomes relevant where different firms at different levels of the ad-tech chain coordinate on:

exclusionary agreements;

discriminatory access arrangements;

information exchange;

exclusive dealing;

allocation of customers;

coordinated auction practices.

Article 102 TFEU

This is normally the central provision where a dominant ad-tech undertaking is vertically integrated.

Potential abuses include:

self-preferencing;

discriminatory treatment;

tying;

refusal of access;

margin squeeze;

leveraging dominance from one market into another;

discriminatory use of data;

exploitation of commercially sensitive information;

foreclosure of rival DSPs or SSPs.

Digital Markets Act

The DMA adds ex-ante obligations for designated gatekeepers. Alphabet's online advertising service is among the services for which Alphabet has been designated as a gatekeeper. (Digital Markets Act (DMA))

The DMA is particularly relevant to:

advertising-data access;

transparency;

interoperability;

performance measurement;

treatment of business users;

conflicts created by platform control of multiple layers.

3. Why Vertical Integration Creates a Conflict

Vertical integration is not unlawful by itself.

It can produce legitimate efficiencies:

lower transaction costs;

better technological integration;

faster auctions;

improved fraud detection;

better measurement;

reduced latency;

improved matching between advertisers and publishers.

The legal problem arises where integration gives the undertaking the ability and incentive to disadvantage independent rivals or trading partners.

For example:

Company A operates both a DSP and an ad exchange. Its DSP receives information or bidding advantages unavailable to competing DSPs, while the exchange simultaneously imposes conditions that favour the group's own DSP.

Potential legal questions become:

Is the undertaking dominant?

What are the relevant markets?

Are the different ad-tech layers separate markets?

Does the undertaking control an important input or interface?

Does it favour its own downstream service?

Can the conduct foreclose equally efficient competitors?

Is there actual or potential harm to competition?

Are advertisers or publishers harmed?

Are there objective justifications or efficiencies?

What compensation can injured parties obtain?

4. Important Forms of Ad-Tech Vertical Conflict

A. Self-preferencing

A vertically integrated platform may give its own DSP, SSP or exchange preferential treatment.

Examples:

priority access;

better ranking;

faster information;

preferential auction rules;

preferential fees;

privileged technical integration.

This is closely connected with the principles developed in Google Shopping.

B. Discriminatory access

An integrated ad-tech provider may give rival services:

inferior technical access;

delayed access;

less complete data;

more expensive access;

restrictive APIs;

reduced functionality.

The question is whether the discriminatory conditions disadvantage competitors sufficiently to constitute exclusionary abuse.

C. Margin squeeze

A vertically integrated undertaking could charge a high price at the upstream level while competing downstream at a price that rivals cannot profitably match.

The classic formula is:

High upstream cost + low downstream price = insufficient rival margin

This principle is particularly relevant to vertically integrated ad-tech businesses.

D. Use of competitors' confidential information

An integrated platform may obtain commercially sensitive information from:

advertisers;

publishers;

rival DSPs;

rival SSPs;

agencies.

The legal issue is whether that information is subsequently used to favour the integrated firm's competing service.

E. Auction manipulation

Programmatic advertising is largely auction-based.

Potential conflicts include:

preferential bidding;

altered auction mechanics;

discriminatory access to bid information;

preferential treatment of affiliated participants;

manipulation of fees;

withholding information from independent participants.

This is especially important because an integrated undertaking can potentially influence both sides of the transaction.

5. Case Law

Case 1 — Google and Alphabet v Commission (Google Shopping)

CJEU, Case C-48/22 P, 10 September 2024

This is one of the most important modern European authorities on self-preferencing and leveraging.

Google was found to have favoured its own comparison-shopping service within its general search results. The Court of Justice dismissed Google's appeal and upheld the essential findings concerning abuse of dominance. (Infocuria)

Relevance to ad-tech

The case establishes an important principle:

A dominant platform can potentially abuse its position when it uses an important upstream platform to favour its own downstream service.

The comparison-shopping facts are not identical to ad-tech, but the reasoning is highly relevant to:

dominant ad-tech infrastructure → preferential treatment of affiliated ad-tech service.

Legal significance

The case assists analysis of:

self-preferencing;

leveraging;

foreclosure;

effects on competitors;

causation;

as-efficient-competitor analysis;

competition on the merits.

6. Case 2 — Slovak Telekom v Commission

CJEU, Case C-165/19 P, 25 March 2021

Slovak Telekom concerned access to telecommunications infrastructure and margin squeeze.

The Court considered the relationship between wholesale access conditions and downstream competition. (Infocuria)

Ad-tech application

Suppose an integrated ad-tech company:

controls an important upstream exchange or infrastructure;

charges competitors substantial upstream fees;

simultaneously operates a downstream DSP;

gives its own downstream business commercially favourable conditions.

A margin-squeeze analysis could become relevant.

Principle

Vertical integration does not permit a dominant undertaking to structure upstream and downstream pricing in a manner capable of excluding equally efficient competitors.

7. Case 3 — Deutsche Telekom v Commission

CJEU, Case C-280/08 P, 14 October 2010

The Court confirmed that margin squeeze itself can constitute an abuse of dominance.

The relevant question is whether the dominant undertaking's pricing structure makes it difficult for an equally efficient competitor to compete downstream. (curia)

Ad-tech relevance

Imagine:

Ad exchange → high access fee

while simultaneously:

Affiliated DSP → favourable downstream economics

Independent DSPs may be unable to compete even though they are technologically efficient.

The case therefore provides an analytical framework for examining vertically integrated ad-tech pricing.

8. Case 4 — Servizio Elettrico Nazionale and Others

CJEU, Case C-377/20, 12 May 2022

This case concerned ENEL's vertically integrated structure in the Italian electricity market.

The Court examined exclusionary conduct and the use of commercially sensitive information within a vertically integrated corporate group. (Infocuria)

Ad-tech importance

This is particularly useful for ad-tech because information flows are fundamental to advertising markets.

An integrated group might possess information concerning:

advertiser demand;

publisher inventory;

bid prices;

audience characteristics;

conversion performance;

competing platforms.

If commercially sensitive information obtained through one part of the stack is strategically used by another part, Article 102 analysis may arise.

Important principle

The existence of vertical integration does not itself prove abuse, but the use of advantages obtained from one market to exclude competitors in another market can be highly relevant.

9. Case 5 — Google and Alphabet v Commission, General Court

General Court, Case T-612/17, 10 November 2021

This was the first major judicial stage of the Google Shopping litigation before the CJEU's 2024 judgment.

The General Court upheld the Commission's central finding that Google had favoured its own comparison-shopping service and examined:

dominance;

leveraging;

foreclosure;

effects;

competition on the merits;

objective justification. (Infocuria)

Ad-tech relevance

It provides a useful analytical analogy for:

dominant infrastructure + affiliated downstream service + preferential treatment.

That structure is potentially similar to:

dominant advertising infrastructure + affiliated DSP/SSP/exchange.

10. Case 6 — Bronner

CJEU, Case C-7/97, 26 November 1998

Bronner is a foundational case concerning refusal of access to an infrastructure controlled by a dominant undertaking.

The Court established stringent conditions for imposing a duty to supply/access under Article 102.

Ad-tech relevance

An ad-tech platform may control infrastructure that rivals claim is indispensable.

Examples:

access to an ad exchange;

access to particular technical interfaces;

advertising inventory;

measurement infrastructure;

essential interoperability.

However, simply saying that a platform is commercially important is not enough.

The Bronner-type indispensability analysis can become important where a rival seeks mandatory access.

11. Case 7 — United Brands v Commission

CJEU, Case 27/76, 14 February 1978

United Brands is a foundational Article 102 case concerning dominance and exclusionary conduct.

The Court's broader approach demonstrates that Article 102 focuses on whether an undertaking holding a dominant position uses methods different from those governing normal competitive conditions.

Ad-tech relevance

A dominant ad-tech business cannot rely on its technological sophistication alone as a justification for conduct that has exclusionary characteristics.

Relevant questions include:

market power;

barriers to entry;

customer dependence;

alternative technologies;

network effects;

data advantages;

switching costs.

12. Case 8 — Intel v Commission

CJEU, Case C-413/14 P, 6 September 2017

Intel is important for analysing exclusionary effects and rebates.

The Court required attention to the economic circumstances surrounding potentially exclusionary conduct rather than treating every form of rebate mechanically.

Ad-tech application

An integrated advertising platform might offer:

preferential rebates;

volume discounts;

loyalty incentives;

bundled advertising services;

discounts conditional on using affiliated infrastructure.

The legality depends upon the circumstances and effects, including whether the conduct is capable of restricting competition.

13. Direct 2025 Google Ad-Tech Decision

The most directly relevant European development is European Commission Case AT.40670 — Google Adtech and Data-related Practices.

The Commission adopted its prohibition decision on 5 September 2025, under Article 102 TFEU and Article 54 EEA. The published case record identifies Google and Alphabet as the undertakings concerned. (Competition Case Search)

The Commission's decision addresses Google's presence throughout the ad-tech value chain and its alleged ability to favour its own services. The published decision discusses different forms of conduct on both the buy side and sell side. (European Commission)

This is particularly important because it moves the subject from analogy into a directly investigated ad-tech vertical-integration dispute.

However, it should be distinguished from a CJEU judgment: a Commission decision is an administrative competition decision and may be subject to judicial review.

14. Civil-Law Claims Arising From Ad-Tech Integration

Although the principal regulatory framework is competition law, affected parties may have civil/private-law consequences.

Possible claimants include:

Advertisers

Potential losses:

excessive advertising costs;

reduced advertising effectiveness;

discriminatory access;

inflated transaction costs;

loss of campaign opportunities.

Publishers

Potential losses:

reduced advertising revenue;

discriminatory treatment;

reduced auction proceeds;

inability to obtain competitive bids.

Rival DSPs/SSPs

Potential losses:

foreclosure;

lost customers;

lost revenue;

reduced market access;

increased costs.

Consumers

Potential consequences can include:

reduced choice;

higher prices indirectly caused by advertising costs;

privacy-related harm;

reduced service quality.

15. Private Damages Actions

A competition infringement can potentially lead to private damages litigation.

The claimant normally needs to establish:

Infringement → causal connection → actual loss → quantification

Possible damages include:

overcharges;

lost profits;

lost customers;

lost market opportunities;

additional costs;

interest.

The claimant must still satisfy applicable national procedural and damages rules.

16. Causation Problems

Ad-tech cases create unusual causation difficulties.

For example:

A publisher claims that discriminatory ad-exchange treatment reduced its advertising revenue by €10 million.

The defendant may argue that the decline was instead caused by:

reduced advertising demand;

changes in consumer behaviour;

economic recession;

competing platforms;

changes in privacy rules;

changes in browser technology;

seasonal effects.

Therefore, the claimant may require:

auction records;

historical bid data;

counterfactual modelling;

platform logs;

transaction data;

econometric evidence.

17. Data as a Vertical-Integration Advantage

Data is particularly important.

An integrated ad-tech group can potentially obtain information from multiple levels:

Advertiser data + publisher data + auction data + user data + measurement data

This may create a competitive advantage.

The legal analysis may involve:

Article 102 TFEU;

GDPR;

DMA;

contractual confidentiality;

trade-secret protection;

data-access obligations.

A competition case and a privacy case can therefore arise from the same technical architecture, but they address different legal interests.

18. Conflict-of-Interest Problem

A vertically integrated ad-tech business can potentially occupy three positions:

Agent for the advertiser

Intermediary operating the auction

Technology provider to the publisher

This can create structural conflicts.

For example:

The intermediary receives information about how much an advertiser is willing to pay while simultaneously operating technology used by the publisher and competing for the same transaction.

The central legal question is not simply whether a conflict exists, but whether the undertaking uses its structural position in a manner prohibited by competition law or other applicable civil/regulatory rules.

19. Self-Preferencing vs Legitimate Integration

A critical distinction must be maintained.

Legitimate integration may include:

faster processing;

technical compatibility;

improved fraud prevention;

better measurement;

lower costs;

enhanced security;

reduced latency.

Potentially problematic conduct may include:

preferential access;

discriminatory pricing;

preferential auction rules;

discriminatory ranking;

exclusive access;

misuse of confidential information;

systematic foreclosure of competitors.

Therefore:

Vertical integration ≠ automatic illegality.

The legal analysis focuses on dominance, conduct, foreclosure capability/effects, competitive process, objective justification and applicable regulation.

20. Role of the DMA

The DMA creates an additional layer of regulation.

For advertising-related gatekeeper services, obligations concerning access to advertising-performance information are particularly significant. The Commission explains that Article 6(8) requires a gatekeeper, upon request and free of charge, to provide advertisers, publishers and authorised third parties with access to relevant performance-measurement tools and data necessary for independent verification. (Digital Markets Act (DMA))

This is important because traditional ad-tech markets can suffer from an information asymmetry:

Platform knows auction performance → advertiser/publisher cannot independently verify it.

DMA obligations therefore complement traditional Article 102 analysis.

21. Ad-Tech Vertical Integration and Merger Control

Vertical integration can also arise through acquisitions.

A merger may combine:

DSP + SSP;

exchange + publisher ad server;

advertiser platform + measurement platform;

data provider + ad exchange.

Competition authorities may examine whether the transaction creates:

foreclosure;

data advantages;

increased entry barriers;

interoperability restrictions;

access discrimination;

incentive to raise rivals' costs.

The Google ad-tech investigation itself reflects how authorities examine the structure of the entire value chain rather than looking at only one isolated service. The Commission's merger materials describe Google's presence across advertisers, DSPs, SSPs, exchanges, ad servers, networks and publishers. (European Commission)

22. Hypothetical Example

Assume AdTechCo operates:

DSP A;

Ad Exchange B;

SSP C;

Publisher Ad Server D.

An independent DSP, RivalDSP, alleges:

Exchange B gives DSP A faster access to auction information.

DSP A receives lower transaction fees.

SSP C provides more valuable publisher data to DSP A.

RivalDSP pays higher fees.

AdTechCo uses RivalDSP's bidding information to improve DSP A.

Publisher Ad Server D gives preferential inventory access to Exchange B.

A European competition analysis would ask:

Step 1

Is AdTechCo dominant in one or more relevant markets?

Step 2

Are the different ad-tech services separate markets?

Step 3

Does vertical integration create an ability to discriminate?

Step 4

Does AdTechCo have an incentive to favour DSP A?

Step 5

Is RivalDSP capable of being foreclosed?

Step 6

Can the conduct be replicated by an equally efficient competitor?

Step 7

Are there legitimate efficiencies?

Step 8

What is the counterfactual?

Step 9

Did advertisers/publishers/rivals suffer measurable loss?

Step 10

What remedies or damages are available?

23. Case-Law Comparison

24. Remedies

Possible remedies depend on the legal route.

Competition remedies

prohibition of discriminatory conduct;

access obligations;

non-discrimination;

interoperability;

behavioural remedies;

information separation;

data-access requirements;

structural remedies in exceptional circumstances;

fines.

Civil remedies

Affected parties may seek:

damages;

restitution;

contractual remedies;

injunctions;

declaratory relief;

interest.

Regulatory remedies

Under the DMA and data-protection regimes, additional compliance measures may arise.

25. Important Distinction: Competition Claim vs Civil Claim

This distinction is essential for examination.

Competition authority proceeding

Authority → undertaking

Objective:

Protect competitive process and enforce competition rules.

Private civil action

Injured party → undertaking

Objective:

Obtain compensation or another private remedy.

A Commission finding can be highly important evidence in subsequent private litigation, but the claimant still has to establish the elements required by the applicable private-law regime.

26. Key Legal Issues

The major issues in European ad-tech vertical-integration disputes are:

Relevant market definition

Dominant position

Vertical integration

Self-preferencing

Leveraging

Refusal of access

Margin squeeze

Discriminatory pricing

Auction manipulation

Data advantages

Confidential information

Foreclosure

Equally efficient competitor

Counterfactual analysis

Objective justification

Efficiencies

DMA obligations

GDPR interaction

Private damages

Causation

Loss quantification

Joint corporate liability

Access to evidence

Cross-border jurisdiction

Limitation periods

27. Conclusion

Ad-tech stack vertical integration is not unlawful merely because one company controls multiple levels of the advertising chain. The central European legal question is whether that structure is used in a manner capable of distorting competition—for example through self-preferencing, discriminatory access, margin squeeze, exploitation of commercially sensitive information or other exclusionary practices.

The most directly relevant modern development is the European Commission's 2025 Google ad-tech decision, while Google Shopping, Slovak Telekom, Deutsche Telekom, Servizio Elettrico Nazionale, Bronner, United Brands and Intel provide the principal judicial doctrines needed to analyse the issue. (Competition Case Search)

For a civil damages claim, the crucial chain is:

Dominance → vertical integration → abusive conduct → foreclosure/competitive harm → causation → quantifiable loss → civil remedy.

Exam Keywords

Ad-tech stack – vertical integration – Article 102 TFEU – self-preferencing – leveraging – DSP – SSP – ad exchange – publisher ad server – auction manipulation – margin squeeze – discriminatory access – data advantage – commercially sensitive information – foreclosure – equally efficient competitor – counterfactual – objective justification – efficiencies – DMA – private damages – causation – loss quantification – competition on the merits.