Google’s display advertising empire faces coordinated pressure on both sides of the Atlantic after the European Commission issued a €2.95 billion fine and the U.S. Department of Justice moved to structurally break up key parts of the company’s ad tech stack. Together, the actions target the same alleged harm: that Google has used its dominance across tools for buying, selling, and auctioning display ads to tilt the open web’s market in its favor.
What the EU decided
The European Commission concluded that Google abused its position in the interlocking markets for publisher ad servers and ad exchanges, where ads are bought and sold in milliseconds. Regulators framed the penalty as more than a one-off punishment, saying the behavior created inherent conflicts of interest that raised advertiser costs and reduced publisher revenues—costs that ultimately flow to consumers.
Brussels also pointed to Google’s history. The new fine follows earlier EU decisions over shopping search, Android tying, and search advertising exclusivity, each carrying penalties exceeding €1 billion. In keeping with that pattern, the Commission signaled that money alone won’t fix the ad tech problem, giving Google a short window to propose remedies and stating that a structural solution—such as divesting parts of its display ad business—may be the only durable path.
At the core of the EU’s case is vertical integration: Google operates the dominant publisher ad server once known as DoubleClick for Publishers (DFP) and runs the ad exchange historically branded AdX, letting the company both stage and participate in auctions. That setup, the Commission argues, enabled preferential treatment that stifled rivals and suppressed fair price discovery.
Inside DOJ’s proposed breakup
In the U.S., a federal court already found that Google engaged in anticompetitive conduct to maintain monopoly power in open-web display advertising. Building on that finding, the DOJ filed a proposed final judgment that would force Google to sell AdX and bar it from returning to the ad-exchange market for a defined period. Regulators cast the divestiture as the fastest way to remove the conflict of running the marketplace while owning the house bid.
The plan goes further on transparency. It would require Google to publish the auction logic used in DFP under an open-source license and have those auctions run by a neutral third party, making the rules visible to buyers and sellers alike. The government also reserved the right to seek additional divestitures if competition does not improve and proposed limits on self-preferencing, plus data portability and interoperability obligations, to prevent a reconstitution of market power.
Notably, the DOJ calls for clawing back a portion of profits linked to the conduct until divestitures close, with funds earmarked for standing up open-source auctions and offsetting publisher switching costs. It is an unusual attempt to reshape market plumbing, not just sanction past behavior.
Why AdX and DFP matter
Programmatic display advertising runs on split-second auctions that match advertisers to available impressions across the open web. AdX historically cleared a large share of those auctions, while DFP, the leading publisher ad server, managed inventory and decided which bids win. According to U.S. court findings, AdX held more than half of its market; DFP’s publisher ad server share was around nine in ten. The UK Competition and Markets Authority has reported similar concentration and conflict concerns, concluding that vertical integration between ad server and exchange created powerful self-reinforcing advantages.
In plain terms, if you control the pipes that route demand and the marketplace that sets the price, you can quietly influence outcomes: who sees which bid, when, and on what terms. That is why both Brussels and Washington are targeting separation and transparency—forcing the auction rules into the open and the exchange into independent hands could reshape incentives and allow rivals to compete on price and quality rather than access.
Industry response and risks
Google says the Commission’s decision is wrong and plans to appeal. The company argues that its ad tech products create value for publishers and advertisers and warns that forced divestitures would introduce friction that ultimately harms smaller businesses. Earlier, Google floated interoperability commitments that would make it easier for publishers to use non-Google tech alongside Google Ad Manager without selling off units.
Publishers and trade groups see it differently. The News/Media Alliance welcomed tougher remedies, saying years of market power in ad tech have siphoned revenue from content producers. Their concerns stretch beyond auction mechanics to broader platform dynamics, including the impact of AI-generated summaries on referral traffic. Advertisers, for their part, continue to press for visible fees and fewer conflicts in the supply chain, echoing themes raised by watchdogs and industry studies on transparency and take rates.
There are execution risks. Spinning off AdX demands a buyer with the scale, neutrality, and engineering heft to handle peak auction volumes and latency tolerances measured in milliseconds. Open-sourcing auction logic is laudable for trust, but governance, versioning, and security will matter; the code must not become a new bottleneck or target for exploitation. And any migration away from entrenched ad servers is nontrivial for publishers with complex yield setups built over years.
What to watch next
In Europe, the immediate test is whether Google proposes a remedy that satisfies the Commission’s call for structural change. In the U.S., eyes turn to the court: if the judge signs the DOJ’s plan largely intact, it would mark the most consequential restructuring of a digital platform since the modern antitrust era began, more akin to a utility-style unbundling than a behavioral consent decree.
However the legal chessboard resolves, the direction of travel is clear. Regulators want to pry apart the most sensitive junctions in the ad tech stack, inject transparency into auctions that have long been opaque, and give the open web a shot at more competitive pricing. For publishers and advertisers who depend on that infrastructure, the next chapter could reset the rules that determine where every programmatic dollar lands.