DOJ Pushes for Google Ad Manager Breakup as Remedies Trial Kicks Off

The U.S. Department of Justice (DOJ) is pressing ahead with its landmark antitrust case against Google’s advertising empire, asking a federal judge to order the breakup of Google Ad Manager as the remedies trial begins this week in Alexandria, Virginia.

This phase of the case follows Judge Leonie Brinkema’s April ruling that Google illegally monopolized the publisher ad server and ad exchange markets by tying its DoubleClick for Publishers (DFP) ad server with AdX, its dominant ad exchange. Claims tied to Google’s acquisitions and advertiser ad networks, however, were dismissed.

What’s on the Table

The DOJ is seeking structural remedies, which could go as far as forcing Google to divest AdX and possibly DFP—core components now bundled within Google Ad Manager. Such a divestiture would be one of the most significant regulatory interventions in the history of digital advertising, reshaping the open-web display ad ecosystem.

Google, unsurprisingly, sees this as a step too far. The company argues that a breakup would “disrupt publishers and raise costs for advertisers,” and instead suggests behavioral remedies focused on interoperability. In short, Google wants to keep its stack intact but allow competitors more access to its advertiser bids in real time—essentially opening the door without giving up the house.

Google’s Defense

Google is doubling down on its appeal of the earlier liability decision and is framing the DOJ’s approach as regulatory overreach. In filings and public statements, the company insists that the government’s proposed remedies “go far beyond the Court’s liability decision and the law.”

The alternative solution Google is floating centers on technical adjustments:

• Allowing third-party ad servers to access AdX’s real-time bids.
• Phasing out Unified Pricing Rules that critics say tilt the playing field.

From Google’s perspective, this interoperability approach is less disruptive and still addresses the concerns raised by the court without the chaos of a structural breakup.

Why This Case Matters

If the court sides with the DOJ, the digital ad market could face its biggest shake-up in two decades. Publishers might gain more leverage by not being locked into Google’s end-to-end ecosystem, and rival ad-tech players could finally compete on a more level field. But for smaller publishers, a forced transition away from integrated Google tools could add new complexities and costs at least in the short term.

On the other hand, if the judge backs Google’s interoperability plan, the ad-tech status quo would largely remain intact—albeit with more transparency and flexibility. That outcome might keep the market familiar while still giving competitors a fighting chance.

Looking Ahead

Even if the court orders divestiture, don’t expect immediate changes. Google has already pledged to appeal the liability decision, which could delay remedies for months, if not years. In the meantime, uncertainty looms for advertisers, publishers, and the broader digital marketing ecosystem.

Bold Outlook’s Take

This case isn’t just about Google—it’s about how much control a single company should have over the plumbing of the digital advertising market. Google has long argued that integration creates efficiency. The DOJ counters that it stifles competition. Both points are true, and that’s the tension regulators face: dismantling efficiencies to foster competition may leave short-term pain but could open the market for new innovation.

Regardless of the outcome, this trial represents a watershed moment in the broader debate over Big Tech’s dominance. If Google is forced to sell off AdX or DFP, it could mark the start of a new era in antitrust enforcement, one where behavioral fixes alone aren’t enough to rein in market power.