Federal courts found Google violated antitrust law in two separate digital advertising markets.
Here is what the judges said about the conduct, and why it matters for businesses that paid for
Google Ads.
When businesses file a Google Ads billing dispute or seek a Google Ads overcharge refund, they often know intuitively that something was wrong with their ad costs, but they may not know exactly what the courts found. Two separate federal judges have now answered that question in detail. Their findings describe specific mechanisms through which Google manipulated auction outcomes, suppressed competition, and denied advertisers the benefits of a competitive market. The opinions, taken together, constitute the most consequential judicial record ever assembled on the economics of digital advertising.
The Search Advertising Market and Judge Mehta’s Findings
On August 5, 2024, U.S. District Judge Amit Mehta of the District of Columbia issued a nearly 300-page opinion in United States v. Google LLC, concluding that Google is a monopolist and that it had acted as one to maintain its monopoly. The ruling found that Google violated Section 2 of the Sherman Antitrust Act by illegally maintaining monopoly power in the markets for general search services and general search text advertising. At the time of trial, the court found that Google held approximately 90% of the market for searches conducted on desktop computers and nearly 95% of searches on smartphones, and an 88% share in the search text advertising market specifically. That degree of dominance, sustained over many years, was central to the court’s analysis of how advertisers were affected.
The conduct at the center of Judge Mehta’s findings was a web of exclusive agreements with device manufacturers, browser developers, and wireless carriers. These arrangements guaranteed Google would appear as the default search engine across the dominant access points to the internet. The court found that these arrangements were exclusionary dealing contracts that foreclosed a substantial share of the market, deprived rival search engines of the user data needed to compete, and reduced rivals’ incentives to invest and innovate. In quantitative terms, the court found that Google’s exclusive distribution agreements foreclosed 50% of the general search services market by query volume, and 45% of the general search text advertising market. The practical consequence was that rival search engines were denied access to the most efficient channels of distribution, leaving them unable to achieve the scale necessary to compete.
The scale of these arrangements was documented in the record. Google paid approximately $26.3 billion in 2021 alone to secure its default search position across devices and browsers. The single largest share of that sum, an estimated $20 billion, went to Apple, reflecting the exceptional commercial value Google placed on being the default search engine on iPhones and other Apple products. The remainder was distributed among device manufacturers, browser developers, and wireless carriers under similar exclusive arrangements.
The court found these payments had allowed Google to entrench its dominance in search text advertising for more than a decade. The opinion described a self-reinforcing dynamic in which Google’s monopoly position in search enabled it to charge supracompetitive prices for search text advertising, and the revenue from those prices was then reinvested into distribution payments that preserved the default arrangements and funded product development. The court found this feedback loop ensured that rivals remained at a persistent competitive disadvantage and that new entrants could not achieve the scale needed to compete. The scale disparity was stark. The court found that Google received nine times more search queries per day than its rivals combined, and nineteen times more on mobile.
The opinion also found that Google’s conduct directly affected the pricing and quality of search text advertising in ways that harmed advertisers. The court found that Google set the prices of its text ads without considering competitors’ prices, conduct that would not have been possible without monopoly power. It further found that Google’s practices, including adjustments to its ad auctions and the removal of granular data from Search Query Reports, reduced advertisers’ autonomy over their own campaigns and contributed to elevated ad prices. For businesses seeking a paid search refund or a Google advertiser refund, this is an important finding as the court found that prices were elevated by anticompetitive conduct, rather than by market forces.
In its December 2025 final remedies order, the court required Google to publicly disclose material changes to its ad auction systems, an acknowledgment that opacity in auction mechanics had itself been part of the problem. The court also barred Google from entering into or maintaining exclusive agreements for distributing Google Search across devices and browsers, targeting the very conduct at the heart of the liability finding. Google has since appealed the verdict and the DOJ has filed a cross-appeal, seeking stronger remedies against Google.
The Display Advertising Market and Judge Brinkema’s Findings
On April 17, 2025, U.S. District Judge Leonie Brinkema of the Eastern District of Virginia issued a 115-page opinion in United States et al. v. Google LLC, finding that Google had willfully engaged in a series of anticompetitive acts to acquire and maintain monopoly power in the open-web display advertising market. The court found Google liable for monopolizing two distinct markets, publisher ad servers and ad exchanges, and for unlawfully tying its products in those markets together in violation of Sections 1 and 2 of the Sherman Act. The opinion found that Google’s DoubleClick for Publishers held at least 91% of the worldwide market for publisher ad servers from 2018 to 2022. Google offered justifications for the tie between its ad server and its exchange, arguing that the arrangement served technical purposes such as reducing spam, fraud, and latency. The court examined each of those justifications and rejected them, finding that none reflected Google’s true motivation for the policy.
Judge Brinkema’s opinion identified specific auction manipulation mechanisms by name. The first was called First Look. Google required publishers using its DoubleClick for Publishers ad server to give Google’s AdX exchange the first opportunity to bid on each ad impression. If AdX met a minimum floor price, it won the auction outright, without competing exchanges ever getting to bid, even when rivals might have offered more. The court found this practice anticompetitive.
The second mechanism was called Last Look. In what publishers understood to be a sealed auction, AdX was given the ability to see the highest competing bid from a rival exchange and then adjust its own bid accordingly before the auction closed. The court found this to be among the most damaging of Google’s anticompetitive practices, one that entrenched its monopoly power, disadvantaged publisher customers, and corrupted the competitive process at its core. The entire premise of a sealed auction rests on a single principle that no bidder can see what others have offered. Google gave its own exchange precisely that ability, turning what publishers believed was a fair and confidential process into something fundamentally different.
The court’s record also documented how publishers attempted to resist these dynamics. Publishers developed a practice known as header bidding, which allowed multiple ad exchanges to compete simultaneously for inventory before the publisher’s ad server made a final decision. The court found that publishers turned to header bidding specifically to try to erode DoubleClick’s dominance and attract more competitive bids. That effort failed, the court found, because Google responded by implementing Last Look and other measures that enhanced the structural advantages of the AdX-DFP combination and neutralized the competitive threat that header bidding posed.
A third policy, called Unified Pricing Rules, prohibited publishers from setting higher floor prices for AdX than for other exchanges. By preventing publishers from pricing AdX at a premium, even when AdX was winning auctions through the structural advantages described above, Google reduced publishers’ ability to control their own revenue and foreclosed a mechanism that could have corrected for AdX’s built-in edge. The court also found that a feature called Dynamic Revenue Share was anticompetitive. Through that mechanism, Google algorithmically varied the share of auction revenue it took from publishers depending on what was needed for AdX to win a given impression, allowing AdX to undercut rival exchanges on price in a way that was invisible to the market and impossible for competitors to replicate. Publishers, the court found, felt stuck using DoubleClick for Publishers given its tie to AdX, even as they recognized that these policies worked against their interests.
Taken together, Judge Brinkema concluded that this conduct substantially harmed Google’s publisher customers, the competitive process, and ultimately consumers of information on the open web. The tying of the publisher ad server to the ad exchange meant that publishers who wanted access to AdX were required to use Google’s DoubleClick for Publishers as well, giving Google the leverage to implement and enforce each of these policies across the market. The court found that for over a decade Google charged a 20 percent take rate on each open-web display transaction through AdX, and that this represented a durable supracompetitive price that Google had shown no willingness to lower despite competitive pressure. Because advertisers buying display inventory depended on reaching audiences across the open web, and because that inventory was largely transacted through the infrastructure Google controlled, the court’s findings on publisher harm connect directly to the prices advertisers paid on the buy side.
What These Findings Mean for Advertiser Claims
The two rulings address different segments of the digital advertising ecosystem, but they converge on the same conclusion for businesses evaluating a Google Ads arbitration claim or pursuing a digital advertising refund. The prices they paid were the product of markets that Google controlled through anticompetitive means, not through competition on the merits. In the search market, the mechanism was the exclusion of rival search engines from the distribution channels that would have generated the scale needed to compete on price and quality. In the display market, the mechanism was a set of auction policies that systematically favored Google’s own exchange while preventing publishers and advertisers from accessing genuinely competitive alternatives.
For businesses that spent money on Google search text ads or open-web display advertising, the findings of these two courts provide substantial and well-documented support for private arbitration claims against Google. Advertisers who believe they may have been overcharged as a result of the conduct described in these opinions should consult qualified counsel to evaluate their specific circumstances and the legal options available to them.
This article is provided for general informational purposes and does not constitute legal advice. Businesses seeking to evaluate an advertising claim refund or pursue a Google Ads billing dispute should consult qualified counsel to assess their specific circumstances.