In an antitrust law enforcement decision, on 5 September 2025, the European Commission announced it had fined Google €2.95 billion for abusing its dominant position in online advertising technology (AdTech). This penalty marks the fourth major antitrust sanction against Google in the EU and the Commission found that Google had breached EU antitrust rules by ‘distorting competition in the advertising technology industry’ and ‘favouring its own digital advertising services’.
In addition to the fine, the decision orders Google to end its ‘self‑preferencing’ practices and eliminate the ‘inherent conflicts of interest’ in its ad tech supply chain. Given the wording of the press release, there appears to be a preference on the part of the EU Commission for structural remedies.
The decision has broad significance for digital competition enforcement. It demonstrates Brussels’s resolve to tackle anti‑competitive conduct by dominant platforms and underscores that market leading technology companies are subject to strict EU antitrust and digital markt regulation rules. It is also noteworthy that this fine comes amid heightened US‑EU tensions over Big Tech regulation and may set a precedent for enforcement.
Core Concepts in EU Competition Law
A quick review of core concepts of key EU competition law principles to gain a better understanding of the case:
- Market definition is the first step and the Commission identifies the relevant product and geographic markets where competition is assessed. The product market includes all services that consumers regard as substitutes based on characteristics, prices and uses. The geographic market is the area where sellers face similar conditions of competition. In practice, high market shares and barriers to entry are taken as strong indicators of market power.
- Dominance. Once markets are defined, a firm’s dominant position is assessed. A dominant undertaking is one that is able to act to a large extent independently of competitors, customers or consumers. The Commission, amongst other indicators, considers market share, technological leadership, vertical integration and entry barriers. Critically, being a dominant company is not itself illegal under Article 102 TFEU, but a dominant company bears a ‘special responsibility’ not to distort competition.
- Abuse of dominance under Article 102 occurs when a dominant firm engages in exploitative or exclusionary practices that harm competition. Examples include refusing to deal with rivals, tying/bundling products, predatory pricing, and excessive pricing. In digital markets, ‘exclusionary’ abuses are often the main focus, because it is conduct that keeps rivals out or forecloses competition. Importantly though, Article 102 TFEU does not list prohibited abuses exhaustively and courts apply a flexible standard requiring that the conduct ‘departs from competition on the merits’ and excludes or impairs efficient competitors.
What is ‘self-preferencing’
The evolving doctrine of ‘self-preferencing‘ is central to this case involving Google. It occurs when i.e. a dominant platform operator favours its own products or services over those of rivals on its platform.
The 2017 Google Shopping case is a key precedent. There, Google was found to have placed its own comparison shopping results more prominently than competing services in general search result. The Commission back then imposed a €2.42 billion fine for that abuse. The General Court and ultimately the CJEU confirmed that ‘self-preferencing’can infringe Article 102 if it ‘falls outside the scope of competition on the merits’ and produces exclusionary effects. In other words, a platform operator may include or promote its own content on non‑discriminatory terms, but if it uses its control of the platform to favor its services in a way that stifles equally efficient competitors, it can be illegal. The CJEU emphasised that whether ‘self-preferencing’ is abusive depends on the specific market context, the effect on traffic, the ability of users to switch, etc.
Summary and Analysis of the current Ad Tech Decision
The Commission’s decision, in the current case AT.40670 (the “Google AdTech” case), centres on Google’s online display advertising business. This includes the suite of tools Google provides for serving and buying ads across the open web. In practice, Google’s AdTech stack comprises at least three layers:
- Publisher ad servers (DoubleClick for Publishers, DFP/Ad Manager), software that web and app publishers use to manage, schedule and deliver advertising on their sites. Google’s DFP is by far the most widely-used publisher ad server in Europe.
- Ad exchange (Google AdX), the programmatic marketplace where publisher inventory is auctioned. Google AdX lets publishers sell ad space to the highest bidder in real-time auctions.
- Advertiser platforms (Google Ads and Display & Video 360), tools used by advertisers and agencies to buy display ads. Google Ads (formerly AdWords) and DV360 allow advertisers to bid for impressions across many publisher sites.
The Commission noted that this infrastructure is vertically integrated, giving Google a presence at almost every point in the display advertising supply chain. Publishers rely on its ad servers and exchange to sell banner ads, while advertisers rely on its buying tools to place ads, which means Google often intermediates between the buyer and seller of each ad. In short, Google acts simultaneously as ad buyer, ad seller, and marketplace operator.
The investigation found that Google holds dominant positions in the market for publisher ad servers and market for programmatic ad buying tools for the open web. In addition, Google enjoys substantial entry barriers (thanks to its data assets and pre‑existing relationships with advertisers and publishers) and has vast financial resources. In sum, the Commission determined Google had been dominant in these markets throughout the period under review (from 2014 to today) and possessed the ability to distort competitive conditions.
Abusive Conduct. The core finding is that Google abused this dominance by ‘self-preferencing’ in its ad tech stack, to the detriment of publishers, advertisers, and rival ad tech firms. Concretely, Google apparently did the following:
- It favoured its own advertising exchange (AdX) by avoiding that is proprietary ad buying tools Google Ads and DV360 use rvial ad exchanges thus giving preference to its on ad exchange and consequently making it the most attractive.
- It leveraged proprietary data and features. Google’s ad server collected vast data on all bids in its auctions. The Commission found that Google did use this information to improve its own bid strategies, a practice unavailable to smaller rivals. For example, it apparently passed on information to AdX regarding the highest bid a competitor was willing to make and thus allowing AdX to set the rate accordingly to win the bidding processs.
Illustration by EU Commission.
These practices together meant that Google steered more ad impressions to itself and charged higher fees, while reducing the fill rates and revenues available to publishers and rival networks. The net effect was to distortion of competition in the AdTech sector. In regulatory terms, Google’s ‘self-preferencing’ departs from competition on the merits and excludes efficient rivals precisely the sort of leveraging abuse contemplated by Article 102.
Calculation of the Fine. Under the Commission’s 2006 Fining Guidelines, the penalty for an Article 102 infringement is based on the seriousness and duration of the abuse and on the undertaking’s ability to pay. The €2.95bn figure reflects the high degree of market effects, because the abuse impacted a large share of the online advertising market and was maintained over a long duration (a decade-plus). The Commission also likely increased the standard fine to account for Google’s repeated history of antitrust breaches and partial compliance failures.
Remedies. The Commission ordered Google to end its self-preferencing practices immediately and to eliminate the conflicts of interest in its ad tech products. Google has been given 60 days from the decision to submit proposals for how it will comply. This is in line with EU practice for commitment procedures, where the company must propose effective solutions. After that, the Commission can consult third parties and either accept the commitments or impose its own remedies. In its statement, the Commission reiterated that its preferred remedy would be a structural one, namely, forcing Google to divest part of its adtech business (such as AdX and/or DFP), if Google’s own proposals do not resolve the matter.
Google’s Broader EU Antitrust Record
This AdTech sanction is the latest chapter in a long-running saga between Google and Brussels. The company has been the target of multiple major EU antitrust investigations. Notable cases include:
- Google Shopping (2017): The Commission fined Google €2.42bn for abusing search dominance by giving its own price-comparison service more prominent placement than rivals in search results. The fine was upheld by the General Court and affirmed by the CJEU in 2024.
- Android (2018): Google was fined €4.34bn for tying its search and browser services to the Android mobile platform. This remains the largest antitrust penalty in EU history. Google is challenging this decision (with the fine later reduced slightly on appeal).
- AdSense (2019): The Commission fined Google €1.49bn for restricting third-party websites from displaying search ads from Google’s competitors (the case against the AdSense for Search product). This judgement was anulled by the General Court in 2024 but is currently appealed by the EU Commission before the Court of Justice.
Google’s Broader U.S. Antitrust Record
Google’s AdTech decision comes amid parallel antitrust battles in the United States. In the U.S., the Department of Justice (DOJ) has pursued Google on both search and advertising fronts, but the remedies have so far differed markedly from the EU’s approach.
In the search market, U.S. District Judge Amit Mehta in Washington, D.C. ruled in the U.S. v. Google case in August 2024, that Google illegally maintained a monopoly in online search and related ad markets. The court concluded that Google had used billions of dollars to make its search engine the default on most devices, entrenching a near 90% share.
However, in the remedies phase the U.S. judge largely rejected the DOJ’s demand for a breakup. In a September 2025 order, Mehta allowed Google to keep key assets like its Chrome browser and Android OS, but imposed behavioural requirements. He mandated that Google share more search data with rivals to open up competition. In effect, Mehta achieved some concessions (greater data access) but stopped short of structural remedies. Thus, in the U.S. search case the focus has been on behavioural fixes rather than enforced structural divestiture.
By contrast, the DOJ’s lawsuit against Google’s AdTech activities, case United States et al. v. Google filed in the U.S. District Court for the Eastern District of Virginia, more closely mirrors the EU’s posture. In May 2025, Judge Leonie Brinkema of the Eastern District of Virginia set a trial date (22 September 2025) specifically to consider remedies in the case. The DOJ is explicitly seeking the sale of Google’s publisher ad server and ad exchange (the same products at issue in the EU case). In other words, like Brussels, the U.S. government appears to be pushing for structural separation of Google’s buy-side and sell-side platforms. Judge Brinkema’s order to hold a remedies trial indicates that the U.S. case has already established liability (Google’s conduct is viewed as anticompetitive) and is now focusing on how to restore competition. The contrast is instructive. In the search case, the U.S. system opted for incremental relief; in adtech, it seems willing to entertain a more drastic outcome.
The EU decision likewise reflects a readiness to impose structural remedies if needed, paralleling the DOJ’s strategy in the adtech suit. In both jurisdictions, the interplay of these cases suggests a tough era of antitrust enforcement. Regulators are not only signalling that dominant digital platforms can be sanctioned for self-preferencing, but also that remedies actively sought include breaking up parts of a business if behavioural changes prove insufficient.
Practical Implications
This Commission decision raises important legal and practical questions. First, the form of harm identified, ‘self-preferencing’ in a complex multi‑sided ad exchange, is fairly novel. Unlike classical abuses, such as foreclosure or predation, the alleged harm here was that Google’s integrated adtech chain allowed it to partially exclude competition while still serving customers. Economically, Google’s conduct meant publishers effectively competed against themselves in auctions, reducing their revenue, and advertisers faced a skewed buying environment. Such an ‘internal conflict’ harms the incentive of publishers to rely on independent exchanges. The Commission’s analysis implies that vertical integration by a monopoly can be abusive even if access is not outright denied, so long as the terms of access are unfair to rivals. In practical terms, the ruling shows that EU competition law can and will reach into algorithmic and technical details of platform conduct.
Second, the case highlights the Commission’s remedy strategy. EU law provides both behavioural and structural tools. In recent years, the Commission typically accepted behavioural commitments in digital cases. For example the decisions in Google Android and Google AdSense required Google to change contracts or interfaces. However, this decision signals a tougher stance. The Commission has openly stated that divestiture is its ‘preferred option’ if Google’s solutions fail. In legal terms, the Commission is effectively warning Google that if a voluntary commitment is not enough, it could force it to spin off part of the ad business. This aligns with the DOJ’s approach and shows convergence toward structural remedies for entrenched platform power.
