The April 17 ruling comes in parallel to a separate antitrust case, which Google also lost. The DOJ is pushing for a forced sale of its dominant web browser, Chrome, with developments there also set for significant advancements in the coming months.

Specifically, the court ruled that Google illegally monopolized both the publisher ad server and ad exchange markets, and unlawfully tied those two services together — violating Sections 1 and 2 of the Sherman Act.

However, it’s important to note that the court also dismissed claims that Google monopolized the advertiser ad network market, concluding that the DOJ failed to define a clear market in that space.

With liability now established, the proceedings move into the remedies phase. The DOJ is expected to push for structural relief, most notably the divestiture of Google’s sell-side ad tech stack, including DFP and AdX. If granted, this would mark one of the most consequential antitrust interventions in modern tech history and could fundamentally reshape the digital advertising ecosystem.

In a written statement, Digital Content Next CEO Jason Kint, an executive that has followed the trial closely, both online and in person during the three-week “rocket docket” courtroom proceeding, reaffirmed rulings made in the earlier search antitrust case. “This ruling underscores the global harm caused by Google’s practices, which have deprived premium publishers worldwide of critical revenue, undermining their ability to sustain high-quality journalism and entertainment,” he added.

Mixed ruling spurs Google appeal

Google is expected to appeal the ruling, arguing that the decision misinterprets both the facts of the case and long-standing Supreme Court precedent on antitrust law, particularly in relation to tying arrangements and monopoly maintenance.

Its legal team also claims the ruling misinterprets Supreme Court precedent and contradicts appellate decisions, particularly around obligations to competitors. Its legal team welcomed the dismissal of advertiser-side claims, arguing this strengthens grounds for appeal and undermines the case for structural remedies like divestiture.

Alan Chapell, president of Chapell & Associates, noted how the ruling in Google’s favor was a clearly the weakest link in the DOJ’s case, adding the inherent problems with the advertiser side of the case was the lack of a clear definition of an ad network. “I just thought the publisher side and ad exchange case[s] were really, easy to debate… so that was ruling was not a big surprise,” he adds.

By losing the advertiser-side monopolization claim, Myles Younger, chief growth officer at U of Digital, thinks the DOJ has actually strengthened its hand now that the case is more focused on Google’s sell-side control with DFP and AdX.

By limiting Google’s ability to negotiate or trade off parts of its stack, such as its demand-side platform DV360, it could make structural remedies more likely and giving DOJ clearer legal leverage. He adds, “Google has fewer levers for negotiating this (which gives the DOJ more comparative leverage) because DV360 is essentially off the table… The DOJ seems to have made this 100% about sell side ad tech and exchanges which to me would imply fewer opportunities for horse-trading.”

Now what?

Yet questions remain. Is a forced breakup the most effective — and realistic — remedy? Google’s ad tech infrastructure is deeply interwoven into the media buying process, and a divestiture would be complex and disruptive.

Chapell, who is also author of The Monopoly Report, believes there “is about a 25% chance” Google, despite its protestations and vowing to appeal against both antitrust rulings in the last year, may look to settle.

“I think they’re starting to see writing on the wall,” he says, pointing the parallel remedies trial in the search antitrust proceedings, further predicting that such a settlement could come as soon as this year.

Scott Messer, principal and founder of Messer Media, who maintains any attempt from Google to reach a settlement could result in “an absolute sledgehammer” of a remedy, adds that a forced spin-out of Google Ad Manager will hamstring the performance of AdX.

“There is no way that a divested GAM can integrate with AdX in the same manner, and thus they have no option but to enable [interoperability],” he adds. “Google may appeal, but maybe they’ll just let it go and focus on the real problem of protecting their search products from the threat of AI. Google has their hands full, and I don’t know if sell-side domination is any longer really strategic to their long term vision.”

Advertisers and publishers rely heavily on Google’s end-to-end tools, meaning any break-up could introduce instability in the short term, with Paul Bannister, chief strategy officer at Raptive Media, noting how any remedies should focus on benefiting publishers, not just ad tech companies.

He maintains the court could insist upon interoperability with third-party ad tech, such as forcing AdX demand to be available in Prebid, would address concerns over Google’s domination of the market.

Bannister also thinks efforts should be made to prevenet Google pulling all demand inside its walls, hence any outcome should ensure DV360 and other internal demand sources keep spending on the open web for an extended period of time.

He adds, “I believe the remedy from this case should be combined with the search antitrust case and Google should be compelled to keep sending traffic to the web,” he says. “No more growth in ‘zero-click’ searches. Traffic is the future war.”

Will it make any difference?

Beyond the legal strategy, industry sentiment is mixed.

In a September survey, the majority of Digiday readers claimed a divestiture alone won’t go far enough to create meaningful change.

Many are calling for behavioral remedies, such as forcing Google to fully support header bidding in practice, not just in theory. Critics argue that despite claiming support for open standards, Google’s actions have often undermined independent monetization efforts.

There are also growing concerns that the DOJ’s approach may already be outpaced by the current dynamics of the industry. The rapid rise of AI-driven ad tools, the emergence of retail media networks, and shifting data privacy laws are all reshaping the competitive landscape in real time. Some speculate that Google’s involvement in Scope3’s agentic curation platform may be an attempt to preemptively adjust its business model in response to looming regulatory changes.

Analysts, including those at Arete Research, have floated hybrid remedies — such as certifying divested units as B-Corps or mandating interoperability standards — as potentially more pragmatic alternatives to a blunt divestiture. These options aim to create fairer market conditions without destabilizing the ecosystem.

So what now? Judge Brinkema’s ruling represents a major milestone in U.S. tech antitrust enforcement—but it lands in the middle of a fast-moving, AI-influenced marketplace.

If the remedies are not adapted to current and future realities, the ruling could end up targeting yesterday’s problem, not tomorrow’s. The ultimate outcome must strike a balance: enforce meaningful change while ensuring it remains relevant and sustainable in a rapidly evolving ad tech environment.

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