26 September 2025

Spin-offs, showdowns, and signal loss: Inside Google’s remedies trial

This article follows on from our July piece, If Google’s ad tech empire breaks up, what happens next?, which explored what a forced breakup could mean for advertisers, publishers, and measurement. Now, as the remedies phase unfolds, we revisit the story with new developments from the courtroom.

This article is not written, or presented as legal advice nor opinion. Readers should neither act, nor rely on opinion(s) in this article and linked materials without seeking legal counsel. The following perspectives are drawn from live trial commentary and reporting by sources including daily trial blogs, AP News, Reuters, and The Guardian.

In summary

• The DOJ’s remedies trial kicked off on 22 September in Virginia, setting the stage for proposals that could change the future of Google’s ad tech stack.
• Key considered remedies include spinning off Google Ad Manager (GAM formerly known as Doubleclick for publishers) and Google’s ad exchange Authorised Buyers (formerly AdX), restricting Google’s use of first-party data, and mandating open auction mechanics.
• A ruling could reshape ad tech competition, measurement, and programmatic supply chains globally.
• The DOJ aims to wrap its case by Thursday, with closing arguments tentatively scheduled for 17 November, 2025.

From monopoly ruling to remedies phase

In April 2025, a U.S. federal court found Google guilty of monopolisation across key parts of its ad tech business. As we covered in our original article, any breakup could fragment measurement, weaken Google’s performance edge, and change the economics of digital advertising globally.

Now, the remedies phase will decide whether structural reforms, including divesting Google Ads Manager (GAM) and Authorised Buyers (AdX), are necessary to restore competition.

DOJ pushes for structural remedies

Opening arguments left zero doubt about the DOJ’s position: “Nothing short of a structural divestment is sufficient to bring meaningful change,” argued DOJ attorney Julia Tarver Wood. She described Google’s control as embedded in “algorithms and code” that keep rivals locked out and publishers dependent.

Prosecutors told Judge Brinkema they want Google Ads Manager or other ad tech components sold off entirely, breaking Google’s end-to-end control across the ad tech stack.

This includes Authorised Buyers (AdX), where online publishers currently pay Google a 20 per cent fee to sell ads in real time as users load websites. Regulators argue that owning both the ad server and the exchange lets Google preference its own products and extract more fees from publishers while locking out rivals.

This case differs from the search monopoly ruling, where Judge Amit Mehta decided not to break up Chrome. Here, the DOJ argues Google’s dual control over the ad server (GAM) and exchange (AdX) makes structural separation the only effective remedy.

Google calls the proposal “radical and unnecessary,” claiming it could disrupt the digital ad market and harm publishers rather than help them.

Understanding the remedy scenarios

As the remedies phase unfolds, multiple remedy scenarios are being debated in court. Each represents a different proposal for how to restore competition in the ad tech market following Google’s monopoly ruling. Some focus on structural change (like spinning off parts of Google’s ad tech stack), while others suggest behavioural fixes (like restricting certain practices). None have been decided yet, Judge Brinkema will weigh technical feasibility, market impact, and competition risks before ruling.

Day 1: DOJ versus Google

DOJ opening: Julia Tarver Wood framed Google as a “recidivist monopolist,” arguing that behavioural fixes would be a “game of whack-a-mole,” arguing that breaking up parts of Google’s ad tech stack is the only way to restore competition.

Google’s response? Attorney Karen Dunn called the DOJ’s proposals “radical and reckless,” insisting Google’s own remedies address concerns faster and with less disruption to publishers.

Google’s lawyers argued that AI-driven competition from platforms like Meta and new ad tech entrants shows the market is already evolving, reducing the need for structural remedies.

Witness perspectives

• Grant Whitmore (Advance Local): Public reporting confirms he has raised concerns about how Google’s control over both the ad server and exchange limits publishers’ ability to negotiate and switch tools.
• Andrew Casale (Index Exchange): In filings and testimony, he has argued that Google’s integrated ad tech stack gives it advantages over rivals, and that structural remedies may be required to restore competitive balance.

Day 2: Spin-offs, fees, and frustration

Day two brought a mix of conflicting proposals, frustrated judges, and buy-side opinions.

Judge Brinkema’s reaction: According to sources, the judge grew impatient, saying she wants to hear from technical experts and Google’s engineers rather than industry commentary before ruling on remedies.

Witness divergence on remedies:

• DOJ witnesses backed spinning off AdX first, then reviewing DFP later.
• James Avery (Kevel) argued AdX and DFP must be spun off together or competition issues will persist.
• Buy-side voices like Jay Friedman suggested consolidation or even shutting AdX entirely, citing too many underperforming exchanges already in market.

Publisher vs buyer priorities:

• Luke Lambert (Omnicom) flagged transparency gaps, saying neither DOJ nor Google proposals currently give advertisers or publishers the full visibility they want on auction logic or fees.

Adding to the conversation, tech experts within Louder have noted that breaking up the current model could push up media prices in the short term, hitting smaller publishers hardest, especially as generative AI already reduces their yields through zero-click discovery. But, over the longer term, open-source auction mechanics could level the playing field, driving more competition, transparency, and fairness across the ecosystem.

Fee competition and trust:

• Jay Friedman argued divestiture could spark fee competition and bring down Google’s ad tech take rates.
• Jed Dederick (The Trade Desk) was cited as suggesting that remedies could help restore advertiser trust in open-web display, described by some witnesses as “starving” today.

AI minimal impact so far:

Witnesses agreed that generative AI isn’t yet disrupting ad servers or exchanges, despite Google citing AI innovation as a reason against structural remedies.

Day 3: Expert testimony and economic impact

Professor Robin Lee (Harvard): Testified for the DOJ on the competitive impact of Google’s ad tech dominance.

He presented data showing 89 per cent of AdWords display spend flowed to AdX as of 2022, compared with only 34 per cent to other exchanges.

Lee argued that spinning off AdX would boost competition, drive down exchange fees, and eliminate practices like “First Look” that give Google an unfair advantage .

He also backed a phased divestiture of DFP, saying it would lower switching costs for publishers and open opportunities for rivals.

Judge Brinkema’s questions: Asked whether there is any evidence Google would re-monopolise if only behavioural remedies were imposed, noting “lack of trust has a huge impact” on the remedy decision.

Suggested she may consider behavioural remedies if trust could be guaranteed, but witnesses like Andrew Casale previously argued trust is lacking.

Cross-examination concerns: Google’s attorneys raised “what if” scenarios, for example, if Google shifted all demand to YouTube post-divestiture or withdrew from open web ads entirely, highlighting risks of unintended consequences.

Day 4: Technical feasibility and Google execs under oath

Jon Weissman (Technical Expert): Weissman reviewed Google’s source code and testified that AdX and DFP divestiture, plus open-sourcing Final Auction Logic, are technically feasible.

He explained that Google already has systems in place to separate code dependencies, meaning migration challenges are solvable with existing tools and technology.

Tim Craycroft (Google VP & GM, Advertising): Taking the stand Craycroft confirmed internal projects, Project Sunday (2020/21) and Project Monday (2023/24), evaluated spinning off AdX and DFP.

He admitted divestiture could be done within four years (two before closing, two after) despite Google lawyers previously calling it “unworkable.”

Craycroft’s testimony also revealed that Google has not committed to lowering its 20 per cent AdX take rate, even while offering other incremental concessions to the court. He further confirmed the existence of gBid, a product enabling Google’s buying tools to bypass AdX and bid directly into DFP for mobile app inventory, while expecting stakeholders to accept that it has never been considered for display ads, the focus of this trial.

At one point, Craycroft described the DOJ’s proposed remedies as “naïve” and “terrifying,” yet evidence presented showed Google’s own internal analysis had already confirmed the technical feasibility of separating AdX and DFP.

Finally, Judge Brinkema asked whether removing AdX entirely and letting publishers rely on Prebid auctions could be a simpler solution. Craycroft conceded it might work but raised concerns over quality and fraud, issues the DOJ noted are not unique to AdX.

What’s new since our July article

• Phased divestiture proposals - DOJ proposals reportedly suggest splitting off auction logic first, with full divestiture if competition doesn’t improve.
• First-party data restrictions - Plans would limit how Google uses signals from Search, YouTube, and Chrome across its ad products.
• Global pressure - The EU recently fined Google €2.95B (AU$5.28B) and is considering aligned remedies.
• Investor sentiment - Alphabet’s share price jumped 20 per cent following the search monopoly ruling earlier this month, reaching a $3 trillion valuation. Some analysts see this as a sign markets expect lighter remedies in the ad tech case.
• Publisher concerns - Testimony flagged private marketplace deals and video formats as key areas where Google could retain advantages if remedies don’t go far enough.
• Fallback timelines - DOJ proposals reportedly include a mulit-year review period, up to four years, after which full divestiture could be ordered if competition hasn’t improved.

Louder’s recommendation

As we wrote in July, marketers should prepare for:

• Fragmented measurement - Expect weaker attribution, especially in post-cookie environments.
• Performance headwinds - Automated campaigns like Performance Max may lose cross-platform optimisation benefits.
• Open-source programmatic - A spin-out could bring transparency but also short-term disruption.
• Our full recommendations remain unchanged - build privacy-first data pipelines, diversify measurement strategies, and plan for media cost volatility as the landscape evolves.

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