Google’s ad tech antitrust remedy phase explained — and where the Judge might land

The TL;DR

The DOJ and Google spent 10 (and a half) days arguing over how to fix the tech platform’s illegal monopolization of how online ads are bought and sold as well as the marketplace where it all takes place. Think of this as the penalty phase — not to decide if Google is guilty of the things publishers and ad execs spent years accusing it of, but what the punishment should be. Does Judge Leonie Brinkema force Google to divest the tech that facilitates that control, or are behavioral constraints enough?

What does the DOJ want?

The DOJ’s main ask is ambitious: pry loose Google’s ad exchange — the beating heart of how it monetizes the web. But it doesn’t stop there. The Justice Department also wants the tech company to open-source the code that decides where ads land, a move aimed at breaking publishers’ dependence on Google’s infrastructure. If that doesn’t do the trick, the ad server is next to be divested. Behavioral remedies are in the mix too, but they read more like guardrails — there to keep Google from stitching its ad tech monopoly back together under a new guise.

At the heart of the DOJ’s argument is a simple premise: unless the incentives change, the outcome won’t. So even though the buy side of Google’s ad tech stack wasn’t branded a monopoly, the DOJ kept pointing out that AdWords can’t be left untouched. It’s also why the DOJ argued for expanding AdX access to all inventory types — including private marketplace and video — and routing all bids through a single, transparent channel like Prebid. 

What does Google want?

Google, unsurprisingly, pushed back on the idea of breaking up its ad tech business. Instead, the company floated a series of lighter-touch remedies — tweaks to publisher contracts and interoperability with rival ad servers. The message: no need for a breakup when a few behavioral changes will do.

The numbers behind the drama

• 1 year to implement Google’s proposed remedies, up to 14 years for the DOJ’s.
• 4 years to transfer the AdX exchange to another buyer. Two years to start it, another two to move over all the customers, according to Google’s own internal analysis. 
• 89% of AdWords display ad dollars in 2022, compared to 63% of DV360’s display spend, while only 34% of budgets from other buying platforms, said economic expert Professor Robin Lee.
• 60% of AdX winning auctions had no competition, and of those more than half had AdWords as the only bidder, said Professor Lee. 
• 46% of all indirect open web display advertising goes to AdWords, while DV360 accounted for another 21%, according to Professor Lee. 
• 18 months to develop APIs for migrating data, 24 months to open source the ad server code that makes the final call on which ad to pick, 18 months to migrate AdX exchange, and 24 months to migrate the DfP ad server, according to the technical timeline feasibility expert Dr Goranka Bjedov.
• 66% of the top 100 publishers on Google’s ad server use 10 or more exchanges, according to expert economics witness Andras Lerner.

What the judge is hearing

Throughout this phase of the trial, Judge Brinkema has heard testimony from: 

Publishers: For publishers, the story came through loud and clear: behavioral guardrails won’t cut it. Witnesses argued that Google’s dominance stems from owning both the ad exchange and the ad server tech that decides where ads go, and that only a structural fix would level the playing field. 

Grant Whitmore, vp of ad tech at Advance Local testified that the DOJ’s proposed breakup would be the least disruptive option for publishers not the most, since the burden of change would fall on Google and the new owners of its ad tech instead of the customers of it. Stephanie Layser, formerly of News Corp and now at AWS as global head of publisher ad tech solutions, drove the point home during rebuttals, warning that Google’s auction logic remains a black box — and that behavioral remedies alone leave too much wiggle room. Matthew Wheatland of the Daily Mail backed that view, underscoring how publishers are left in the dark about how ads are routed and why they win or lose bids from Google’s programmatic marketplace. 

The only publisher voice not fully aligned with the DOJ’s stance was Elizabeth Douglas, CEO of wikiHow, who was bought in as a last-minute, surprise witness by Google. She acknowledged AdX’s utility and reliability but described a growing dependency on it that’s hard to unwind, especially as AI driven platforms erode traditional traffic sources. Her testimony highlighted publishers’ fear of disruption more than their frustration with Google.

Rival ad exchanges: The remedies phase of the trial saw the appearance of three note ad exchange CEOs: Andrew Casale (Index Exchange), James Avery Kevel, and Rajeev Goel (PubMatic), with each expressing deep skepticism of Google’s dominance. Collectively, their testimony reinforced calls for structural separation over negotiated fixes, according to observers. Casale argued Google’s ownership of both AdX and DFP distorts competition, while revealing recent talks with the DOJ about potentially bidding for AdX. Meanwhile, Avery underlined how AdX and DFP must be divested together, stressing that fair interoperability is essential for rivals to compete despite scale disparities. Whereas Goel highlighted recurrent issues that block Google’s demand-side platform DV360 from directing spend to his company, arguing that behavioral remedies would fail to address these issues.

Buyside platforms: For buyers, the story was predictable but pointed. Google’s dominance leaves them boxed in. Execs from Omnicom, The Trade Desk, and the former CEO of Goodway Group told the court that accessing must-have inventory often means playing by Google’s rules. They backed some of the changes — like forcing AdX to compete on neutral ground — but voiced trepidation over anything that might snarl up media operations. The consensus: Google’s tools work but that efficiency shouldn’t be the price of competition.

Google execs: Google execs and hand-picked witnesses kept to a familiar refrain: the stack works, it’s efficient and pulling it apart would do more harm than good. The defense mostly held. But the shine faded when internal docs surfaced showing Google had already run the numbers and found a breakup was technically feasible. The argument for status quo didn’t fall apart, but it did wobble. 

What happens next

Trial observers will note the prolonged period between closing arguments during the liabilities phase of the trial (almost a year ago) and the eventual verdict in April of this year — this is despite many expecting a ruling by the close of 2024. With the above caveat in mind, Digiday presents the following outline, based on conversations with close trial watchers.

• Post-trial briefing: ~30 days after close of evidence – late October or early November.
• Closing arguments: ~2 weeks after briefs – mid–to-late November.
• Judge’s ruling: No set date; likely in 2026, not 2025 – say experts.

The smart money is betting on…. Our take is that structural change is on the table for Judge Brinkema, but maybe not the go-to remedy. She’s heard that Google’s dominance stems from control across the ad tech stack, and that even Google internally considered spinning off its ad exchange and ad server. But she’s also heard credible concerns from publishers and agencies about the disruption the breakup could cause. That tension may shape her thinking. 

She pressed witnesses on feasibility and timeline, and questioned whether the DOJ’s more aggressive proposals — like a 10-year oversight regime — would help or hurt the smaller publishers this case is meant to protect. At the same time, Google’s behavioral proposals came off as too shallow. Key witnesses, under cross-examination, conceded that competition could survive great unbundling. 

The likeliest outcome: a set of hard conduct remedies — mandated interoperability, bans on preferential treatment, independent monitoring — with structural divestiture kept in reserve. Judge Brinkema wants enforceable reform that restores competition without lighting a match under the open web. But if Google resists or repeats history, she’ll have a blueprint for stronger action.