Advertising Measurement Monopolies and Attribution Control in Europe

1. Meaning

Advertising measurement monopolies and attribution control arise when one undertaking obtains substantial control over the systems used to determine which advertising activity receives credit for a user's action—for example, an impression, click, installation, purchase, subscription, or conversion—and simultaneously operates important parts of the advertising ecosystem.

A simplified advertising chain is:

Advertiser → DSP/Ad-buying tool → Ad Exchange → Publisher/SSP → Ad → User → Conversion → Measurement/Attribution

The measurement layer can include:

impression measurement;

click tracking;

conversion tracking;

attribution models;

mobile identifiers;

cookies and pixels;

app-install measurement;

cross-device measurement;

campaign analytics;

incrementality testing;

audience measurement;

conversion APIs;

fraud detection.

The competition problem becomes particularly important where the same undertaking controls both advertising infrastructure and measurement infrastructure.

For example, if an undertaking:

sells advertising inventory;

operates an advertising exchange;

supplies measurement tools; and

determines how conversions are attributed,

it may potentially have incentives and opportunities to influence how advertising performance is measured.

That does not by itself establish an infringement. European competition law requires analysis of dominance, conduct, competitive effects and the applicable legal test.

2. Why Attribution Control Matters

Advertising attribution answers a commercially important question:

"Which advertising channel should receive credit for the conversion?"

Consider a consumer who:

sees an advertisement on Platform A;

later searches on Platform B;

clicks a retailer's organic result;

purchases the product.

Different attribution models could assign credit differently:

Last-click attribution

The final click receives 100% of the credit.

First-click attribution

The first advertising interaction receives 100%.

Linear attribution

Credit is distributed across interactions.

Time-decay attribution

Recent interactions receive greater weight.

Data-driven attribution

An algorithm estimates the incremental contribution of different interactions.

The choice can substantially influence:

advertiser spending;

campaign optimisation;

platform revenue;

publisher remuneration;

agency decisions;

competing advertising channels.

Consequently, control over attribution methodology can itself become economically significant.

3. When Does Measurement Become a Competition Concern?

Measurement control becomes particularly important when several conditions occur simultaneously:

1. Dominance

The undertaking has substantial market power in an advertising, platform, measurement or related market.

2. Vertical integration

It operates both measurement infrastructure and another part of the advertising chain.

3. Dependence

Advertisers or publishers cannot easily obtain equivalent measurement elsewhere.

4. Data advantage

The measurement provider possesses data unavailable to competitors.

5. Self-preferencing

The undertaking's measurement system systematically produces advantages for its own advertising services.

6. Interoperability restrictions

Independent measurement providers cannot access necessary data or interfaces.

7. Switching barriers

Advertisers cannot easily migrate historical attribution data.

8. Conflict of interest

The entity measuring advertising performance also earns revenue from the advertising activity being measured.

These factors must be examined together rather than assuming that vertical integration is automatically unlawful.

4. European Legal Framework

A. Article 102 TFEU

Article 102 is the central competition provision where a dominant undertaking allegedly uses its market position in an abusive manner.

Potential theories include:

self-preferencing;

exclusionary access conditions;

discriminatory treatment;

tying;

leveraging;

refusal to provide interoperability;

exploitative conduct;

exclusionary contractual arrangements.

B. Article 101 TFEU

Article 101 becomes relevant where advertising measurement providers, publishers, agencies or other undertakings coordinate through agreements or concerted practices.

Potential issues include:

exchange of competitively sensitive information;

collective restrictions on measurement providers;

exclusionary standardisation;

coordinated restrictions on interoperability.

C. Digital Markets Act

The DMA is particularly relevant to advertising measurement.

The Commission explains that Article 6(8) gives advertisers and publishers, on request and free of charge, access to a gatekeeper's performance-measuring tools and the data necessary for independent verification of advertising inventory. (Digital Markets Act (DMA))

This is directly relevant to attribution control because independent verification reduces the risk that the same gatekeeper becomes the sole authority determining whether its advertising services were successful.

D. GDPR

Attribution frequently involves personal data.

Potentially relevant issues include:

lawful basis;

transparency;

purpose limitation;

data minimisation;

profiling;

cross-service data combination;

consent;

user rights.

Competition law and data protection law can therefore overlap.

5. The Central Competition Problem

The key economic concern can be represented as:

Advertising activity → Data collection → Measurement → Attribution → Advertiser spending

If one undertaking controls all four stages, it may potentially obtain a measurement feedback loop:

More advertising activity → more proprietary data → better measurement → greater advertiser dependence → more advertising activity

This can produce significant economies of scale and scope.

But again:

Scale, integration and proprietary data are not automatically unlawful.

The legal question is whether the undertaking's conduct crosses the applicable competition-law threshold.

6. Case Law

Case 1 — Google Shopping

Google and Alphabet v Commission, C-48/22 P, CJEU, 10 September 2024

This is one of the most important European digital-platform precedents.

The case concerned Google's general search service and its treatment of Google's own comparison-shopping service.

The CJEU upheld the finding of abuse and the €2.4 billion fine. The Court examined Google's favouring of its own specialised search service and the resulting potential anticompetitive effects. (curia)

Relevance to advertising measurement

The case provides an important analogy where a platform controls:

a major user-access point;

ranking;

data;

a downstream service.

In an attribution context, the corresponding concern could be:

a dominant undertaking controls measurement and uses that control to favour its own advertising channel over competing channels.

The exact legal analysis would depend on the conduct and market circumstances.

7. Case 2 — Google AdSense for Search

Google and Alphabet v Commission, T-334/19, General Court, 18 September 2024

This is particularly relevant because it directly involved online advertising intermediation.

Google's AdSense for Search allowed third-party publishers to display advertisements connected to users' searches. The Commission had found abuses involving contractual restrictions.

The General Court ultimately annulled the Commission's decision in its entirety because of errors including the assessment of the duration of the contractual clauses and the market covered by them. (Infocuria)

Importance for attribution control

This case demonstrates that an authority must carefully establish:

the relevant market;

duration of the restriction;

market coverage;

competitive effect;

relationship between contractual restrictions and foreclosure.

Therefore, simply showing that an advertising platform controls important measurement infrastructure would not be sufficient.

The precise competitive mechanism must be demonstrated.

8. Case 3 — Meta Platforms

Meta Platforms and Others, C-252/21, CJEU, 4 July 2023

This case involved Facebook's combination of data from different sources, including information collected from third-party websites and applications.

The CJEU held that a competition authority can, in examining abuse of dominance, take account of whether data processing complies with the GDPR, while respecting the respective competence of data-protection authorities. (Infocuria)

Relevance

This is highly significant for advertising measurement.

A measurement monopoly may depend on combining:

platform data;

advertising data;

website data;

app data;

conversion data;

browsing information.

The case demonstrates that data governance can be relevant to competition analysis.

It does not mean every GDPR violation is automatically an Article 102 infringement.

Rather, the compatibility of data-processing practices may form part of the broader competition assessment.

9. Case 4 — Bronner

Oscar Bronner GmbH & Co. KG v Mediaprint, C-7/97, CJEU, 26 November 1998

Bronner concerned access to a dominant undertaking's newspaper home-delivery system.

The Court established a demanding framework for treating refusal of access to infrastructure as an abuse.

Important considerations include:

indispensability;

absence of viable alternatives;

elimination of effective competition;

objective justification.

(Infocuria)

Application to advertising measurement

Suppose a dominant advertising platform controls a measurement interface containing data that independent attribution providers cannot reasonably reproduce.

A competitor might argue:

"We need access to the measurement infrastructure to compete."

Bronner provides an important analytical framework.

But whether access is legally required would depend on the specific facts, including whether the measurement infrastructure is truly indispensable and whether alternatives exist.

10. Case 5 — Deutsche Telekom

Deutsche Telekom AG v Commission, C-152/19 P, CJEU, 25 March 2021

The case concerned exclusionary conduct in telecommunications and access conditions for competitors.

The CJEU upheld the relevant competition-law analysis and addressed the relationship between regulated access, dominance and exclusionary effects. (curia)

Relevance

Advertising measurement can similarly operate as an infrastructure layer.

For example:

Ad inventory → measurement → attribution → advertiser decision

If competitors depend on an infrastructure controlled by a dominant undertaking, discriminatory or exclusionary access conditions may become important.

The case also demonstrates why the economic characteristics of the underlying infrastructure must be considered.

11. Case 6 — Slovak Telekom

Slovak Telekom v Commission, C-165/19 P, CJEU, 25 March 2021

The case involved access to the Slovak telecommunications network and conditions imposed on alternative operators.

The Court upheld the relevant findings concerning exclusionary access practices. The case is important because access restrictions can be analysed differently depending upon the precise form of the conduct. (curia)

Relevance to advertising measurement

An attribution platform could potentially create similar issues where independent measurement providers require access to:

APIs;

conversion signals;

impression data;

campaign identifiers;

reporting interfaces.

The crucial question is not simply:

"Does the dominant company control the data?"

but:

"How is that control exercised, and does the conduct restrict competition?"

12. Case 7 — Alphabet and Others

Alphabet and Others, C-233/23, CJEU, 25 February 2025

This case concerned Google's Android Auto platform and interoperability with a third-party application.

The CJEU addressed:

digital-platform access;

interoperability;

indispensability;

objective justification;

competitive effects;

downstream markets. (curia)

Relevance to advertising measurement

Attribution providers increasingly depend upon interoperable data systems.

Examples include:

advertiser CRM systems;

mobile measurement platforms;

ad exchanges;

analytics providers;

publisher systems.

If a dominant platform prevents necessary interoperability, the Alphabet judgment provides a useful framework for analysing whether that conduct can amount to an abuse.

13. Case 8 — Deutsche Telekom and Slovak Telekom Combined Principle

The two telecommunications judgments are particularly useful for advertising measurement because they illustrate a broader point:

Control over an infrastructure layer becomes legally important when access conditions affect downstream competition.

Advertising measurement is not physically similar to a telecom network, but economically it may perform an infrastructure-like function where market participants cannot effectively operate without access to measurement data.

The analogy must therefore be applied carefully.

14. Direct Ad-Tech Enforcement: Google AdTech

The most important current European enforcement development is the European Commission's Google AdTech case AT.40670.

The Commission's case concerns Google's online display advertising technology services. Proceedings began in 2021, and the Commission adopted a prohibition decision on 5 September 2025. The Commission found Google had favoured its own online display advertising technology services and imposed a €2.95 billion fine, together with measures aimed at ending the identified self-preferencing and conflicts of interest along the ad-tech supply chain. (Competition Case Search)

The Commission's decision is not itself a CJEU judgment, but it is highly relevant to the present topic because it demonstrates the regulatory concern with vertical control across advertising technology layers.

The Commission's current DMA information also expressly links independent advertising measurement to access by advertisers and publishers to performance-measuring tools and relevant data. (Digital Markets Act (DMA))

15. Attribution Control as a Potential Leveraging Mechanism

Consider a hypothetical undertaking:

Upstream

It controls:

DSP;

advertiser data;

audience data.

Middle layer

It controls:

ad exchange;

auction;

identity infrastructure.

Downstream

It controls:

measurement;

attribution;

reporting.

The undertaking could theoretically influence competition through several mechanisms.

A. Measurement bias

Its own advertising services receive more favourable attribution.

B. Data exclusion

Independent measurement companies receive incomplete data.

C. Delayed reporting

Competitors receive data more slowly.

D. API restrictions

Independent verification becomes technically difficult.

E. Methodology control

The dominant platform determines the attribution methodology.

F. Historical-data lock-in

Advertisers cannot easily transfer historical performance data.

G. Cross-service data advantage

The platform combines information unavailable to independent competitors.

None of these facts alone automatically establishes an Article 102 infringement.

16. The "Measurement Monopoly" Problem

A particularly important concern is single-source measurement.

Suppose:

Platform X sells 60% of an advertiser's digital advertising inventory.

Platform X also determines:

"Platform X generated 70% of the advertiser's conversions."

The advertiser has difficulty independently verifying the result.

This creates a potential measurement conflict of interest.

The economically important distinction is:

Advertising provider

asks:

"How much advertising did we sell?"

Independent measurement provider

asks:

"How much incremental value did the advertising actually create?"

These are not necessarily the same question.

17. Attribution vs Incrementality

This distinction is fundamental.

Attribution

asks:

Which advertising interaction receives credit?

Incrementality

asks:

What additional conversions occurred because of the advertising?

Example:

Without advertising:

1,000 purchases

With advertising:

1,100 purchases

The incremental effect might be:

100 purchases

But a last-click attribution system could allocate credit for many of the 1,100 purchases to advertising even where those customers would have purchased anyway.

Therefore, control over attribution methodology can affect advertiser spending even without changing the underlying consumer behaviour.

18. Data Advantage

A measurement provider may possess information such as:

impression-level data;

click-level data;

conversion events;

identity graphs;

browsing signals;

app events;

transaction data;

campaign histories.

An independent competitor may only receive:

aggregated conversion statistics.

That asymmetry can create a significant competitive advantage.

The Meta Platforms judgment is particularly relevant because it confirms the importance of examining the interaction between data processing and competition-law analysis. (Infocuria)

19. Interoperability

Modern attribution systems frequently require interoperability.

For example:

Advertiser CRM

↓

Conversion API

↓

Advertising platform

↓

Measurement provider

↓

Attribution model

If the dominant platform controls the API, it may potentially control the competitive conditions under which independent measurement providers operate.

The Alphabet C-233/23 judgment provides a useful digital-platform framework for considering access and interoperability, although the factual setting was different. (curia)

20. Self-Preferencing

Self-preferencing may occur where an integrated undertaking gives its own measurement system advantages over rival measurement providers.

Examples could theoretically include:

preferential API access;

faster data;

more granular data;

exclusive conversion signals;

better identity matching;

privileged reporting;

superior auction information.

The Google Shopping judgment is relevant because the CJEU confirmed that favouring a dominant undertaking's own specialised service can constitute an abuse in the appropriate circumstances. (curia)

But the exact Google Shopping reasoning cannot simply be copied mechanically to every attribution dispute.

21. Tying and Bundling

Suppose an advertiser purchases advertising from Platform X.

Platform X says:

"You must use our measurement system if you want access to our advertising inventory."

Potential competition issues may include:

tying;

exclusionary bundling;

foreclosure of independent measurement providers.

The authority would need to examine:

whether the products are distinct;

whether the undertaking is dominant;

whether purchase of one product is conditioned on another;

whether competitors are foreclosed;

whether there are objective justifications or efficiencies.

22. Exclusive Measurement Arrangements

Another possibility is contractual exclusivity.

For example:

An advertiser agrees to use only Platform X's attribution system for five years.

If imposed by a dominant undertaking and covering a significant portion of the market, such arrangements could raise Article 102 questions.

The Google AdSense judgment illustrates why market coverage and duration must be carefully established rather than assumed. (Infocuria)

23. DMA and Independent Verification

The DMA provides an especially important regulatory response to measurement-control problems.

The Commission states that advertisers and publishers may request access to gatekeeper performance-measuring tools and the data necessary for independent verification of advertising inventory. (Digital Markets Act (DMA))

This changes the regulatory model from:

Platform measures → advertiser trusts platform

toward:

Platform provides measurement data → advertiser independently verifies performance.

That distinction is extremely important for attribution markets.

24. GDPR and Attribution

Attribution cannot be separated from privacy law.

Potentially relevant data include:

online identifiers;

cookie identifiers;

advertising IDs;

IP-related information;

browsing activity;

purchase information;

app activity.

Consequently, a competition authority may need to consider whether the data-processing structure is compatible with the GDPR.

Meta Platforms, C-252/21 confirms that a competition authority may consider GDPR compliance in the context of an abuse-of-dominance investigation, while respecting the competence of data-protection authorities. (Infocuria)

25. Economic Effects

A measurement monopoly can potentially create several competitive effects.

1. Foreclosure

Independent measurement firms lose access to customers.

2. Higher prices

Advertisers may face higher measurement or advertising costs.

3. Reduced innovation

Competitors have less incentive to develop alternative attribution methodologies.

4. Lower transparency

Advertisers cannot independently verify advertising performance.

5. Data concentration

More data accumulates with one undertaking.

6. Feedback effects

More advertising activity creates more data, reinforcing the dominant position.

7. Switching costs

Historical measurement data become difficult to transfer.

26. Network Effects

Advertising measurement may also generate network effects.

More advertisers:

→ more campaigns

→ more measurement data

→ better attribution models

→ greater advertiser reliance

→ more advertisers.

Similarly:

More publishers:

→ more inventory

→ more measurement observations

→ more attractive analytics

→ greater platform adoption.

This can create a data-feedback loop.

However, the existence of a feedback loop does not itself establish unlawful dominance.

27. Relevant Market Definition

A major legal issue is deciding what the relevant market actually is.

Possible markets include:

Market A

Online advertising.

Market B

Ad intermediation.

Market C

Advertising measurement.

Market D

Attribution services.

Market E

Mobile measurement.

Market F

Publisher measurement.

Market G

Advertiser analytics.

The correct market depends on:

substitutability;

demand-side behaviour;

supply-side substitution;

technical characteristics;

commercial relationships.

The Google AdSense litigation demonstrates the importance of accurately defining the market and measuring the actual coverage of allegedly restrictive conduct. (Infocuria)

28. Essential-Facility Question

A difficult question is:

When does advertising measurement become an essential facility?

The Bronner test is deliberately strict.

A claimant generally cannot simply say:

"This data would make competition easier."

It must establish the relevant legal conditions for compelled access.

This protects incentives for firms to invest in infrastructure while addressing situations where access may be indispensable for effective competition.

29. Evidence in Attribution Cases

A regulator or claimant would potentially examine:

API documentation;

attribution algorithms;

source code where lawfully obtainable;

data-access logs;

conversion reports;

auction records;

advertiser contracts;

pricing information;

internal communications;

experiment results;

A/B testing;

incrementality studies;

switching rates;

customer complaints;

competitor access;

historical measurement data.

A particularly important comparison is:

Platform-reported attribution vs independently verified attribution.

Large unexplained differences may require further investigation, but they are not by themselves proof of anticompetitive conduct.

30. Causation

Suppose advertisers spend more money on Platform X after adopting its attribution system.

That does not automatically prove foreclosure.

Alternative explanations might include:

genuinely better advertising performance;

lower prices;

superior targeting;

greater reach;

stronger brand recognition;

technological efficiencies.

Therefore, the analysis should ask:

Did measurement control cause the competitive harm, or did superior performance cause greater adoption?

This is a classic competition-law causation problem.

31. Remedies

Possible remedies, depending on the legal findings, could include:

Behavioural

non-discrimination;

interoperability;

API access;

independent verification;

data portability;

transparent measurement methodology.

Structural

In particularly serious circumstances, authorities may examine structural solutions.

The Commission's 2025 Google AdTech decision demonstrates that European enforcement can require measures aimed at addressing conflicts of interest within vertically integrated advertising technology structures. (Competition Case Search)

32. Comparison of Key Cases

33. Important Distinction: Monopoly vs Abuse

The expression "measurement monopoly" should be used carefully.

Having:

80% market share

does not automatically mean:

unlawful monopoly.

Similarly:

owning the dominant measurement system

does not automatically establish Article 102 liability.

European competition law generally asks additional questions concerning:

dominance;

conduct;

exclusionary mechanism;

competitive effects;

objective justification;

efficiencies;

causation.

Therefore, the legally significant concept is generally abuse of a dominant position, rather than merely the existence of a large measurement provider.

34. Future AI Attribution Systems

The issue becomes more complex as attribution becomes AI-driven.

Future systems may estimate:

"This advertisement caused 13.7% of the consumer's purchase probability."

The model could use:

causal inference;

machine learning;

identity graphs;

behavioural signals;

synthetic controls;

reinforcement learning.

Potential problems include:

opaque models;

model drift;

biased training data;

strategic manipulation;

proprietary data;

inability to reproduce results independently.

Thus, AI-based attribution can create a new form of informational market power.

35. Practical Legal Test

A useful European analytical framework is:

D-M-A-C-E-R

D — Dominance
Does the undertaking possess substantial market power?

M — Measurement control
Does it control an important attribution or measurement infrastructure?

A — Access
Can competitors obtain equivalent data and interfaces?

C — Conduct
Has the undertaking engaged in self-preferencing, tying, discriminatory access, exclusivity or other exclusionary conduct?

E — Effects
Is there evidence of foreclosure, higher costs, reduced innovation or reduced competition?

R — Reason/justification
Are there legitimate technical, privacy, security or efficiency explanations?

This is an analytical framework, not a statutory test.

36. Exam-Ready Conclusion

Advertising measurement monopolies and attribution control represent an emerging competition-law issue in which control over the measurement layer of digital advertising may provide an integrated undertaking with significant informational and strategic advantages.

European law does not prohibit vertical integration or proprietary measurement systems merely because they are large. However, where a dominant undertaking controls an important measurement infrastructure and uses that position to restrict access, favour its own advertising services, impose exclusionary conditions, exploit data advantages, or otherwise foreclose competing measurement or advertising providers, Article 102 TFEU and, where applicable, the Digital Markets Act may become relevant.

The leading authorities provide complementary principles:

Google Shopping — self-preferencing and leveraging;

Google AdSense — advertising intermediation, contractual restrictions and market coverage;

Meta Platforms — relationship between data processing and competition law;

Bronner — indispensability and access;

Deutsche Telekom — exclusionary access conditions;

Slovak Telekom — downstream foreclosure and infrastructure access;

Alphabet C-233/23 — digital-platform interoperability.

The most significant current development is the EU's treatment of advertising measurement and independent verification under the DMA, together with the Commission's 2025 Google AdTech enforcement action. The Commission expressly identifies independent access to performance-measuring tools and relevant advertising data as an important safeguard for advertisers and publishers. (Digital Markets Act (DMA))

Ultra-basic rule

Control over advertising measurement is not itself unlawful. The competition-law problem arises where a dominant undertaking uses control over attribution, measurement data or interoperability to obtain or reinforce market power by disadvantaging competing advertising or measurement services.