In January 2023, the U.S. Department of Justice and eight states filed a 153-page antitrust complaint against Google in the U.S. District Court for the Eastern District of Virginia. This summary provides the key allegations from that complaint. The complaint alleges that the company systematically monopolized digital advertising technology through a two-decade scheme to dominate the tools that connect advertisers and publishers.
This summary describes allegations made in the Department of Justice complaint, which Google has denied. Following a trial in 2025, Judge Leonie M. Brinkema found Google liable for monopolizing digital advertising markets.
The Foundation of the Open Internet
The complaint opens with the government’s view of digital advertising’s role in supporting the internet. According to the DOJ, an open internet depends on digital advertising. The complaint describes how website publishers across every industry rely on advertising revenue to fund content creation and distribution, much as newspapers, radio, and television historically depended on advertising to support their operations. But the complaint notes that today’s digital advertising operates on a vastly different scale. According to the government’s filing, U.S. publishers sell more than 5 trillion digital display advertisements annually on the open web. That translates to over 13 billion advertisements every day and generates more than $20 billion in revenue per year for U.S. publishers alone.
The complaint describes how sophisticated technology platforms have developed to automate the matchmaking between website publishers and advertisers. According to the government, every time an internet user opens a webpage with advertising space, these tools almost instantly match that publisher with an advertiser looking to reach that specific user. This process typically involves automated advertising exchanges that run high-speed auctions to identify the best match between publishers selling ad space and advertisers looking to buy it.
The complaint then asserts that competition in this crucial market is broken. The Department of Justice alleges that Google has systematically corrupted the digital advertising marketplace through anticompetitive conduct designed to eliminate or severely diminish any threat to its dominance.
The Core Allegations
The complaint describes Google’s strategy as straightforward but devastating. First, neutralize or eliminate advertising technology competitors through strategic acquisitions. Second, leverage dominance across digital advertising markets to force publishers and advertisers to use Google’s products while disrupting their ability to use competing products effectively.
The result, according to the government, is that a single company with pervasive conflicts of interest now controls the technology used by nearly every major website publisher to offer advertising space for sale, the leading tools used by advertisers to buy that space, and the largest ad exchange that matches publishers with advertisers. As one Google executive reportedly questioned in internal communications: “Is there a deeper issue with us owning the platform, the exchange, and a huge network? The analogy would be if Goldman or Citibank owned the NYSE.”
Read The Entire Complaint Files: Google Ads DOJ Complaint (EDVA) & Google Ads DOJ Complaint (DDC)
The Financial Impact
The complaint highlights a troubling statistic. On average, Google keeps at least thirty cents of each advertising dollar flowing from advertisers to website publishers through Google’s advertising technology tools. Google’s own internal documents reportedly concede that the company would earn far less in a competitive market.
The harm extends beyond direct fees. The complaint alleges that website creators earn less and advertisers pay more than they would in a market where competitive pressure could discipline prices and drive innovation in advertising technology. This conduct affects everyone who uses the internet because as publishers make less money from advertisements, fewer are able to offer content without subscriptions, paywalls, or alternative forms of monetization.
Building the Monopoly
The DoubleClick Acquisition
According to the complaint, Google’s path toward advertising technology dominance began with its 2008 acquisition of DoubleClick. This purchase gave Google control of DFP (DoubleClick for Publishers), the dominant publisher ad server software, and AdX, a nascent ad exchange. This acquisition positioned Google across multiple levels of the advertising technology stack, creating conflicts of interest that the company would allegedly exploit for years to come.
Locking Out Competition
The complaint describes how Google systematically used its position across the advertising technology stack to exclude rivals.
Google restricted access to Google Ads advertiser demand exclusively to its own ad exchange, AdX. Advertisers using Google’s tools could not effectively direct their spending to competing ad exchanges. This gave Google’s exchange an insurmountable advantage in attracting publisher inventory.
Google gave its own ad exchange preferential access within its publisher ad server software. The complaint alleges that Google structured its systems so that AdX could see and respond to competing bids from other exchanges, win inventory before other exchanges could meaningfully compete, and benefit from auction mechanics unavailable to rivals.
Google maintained a 20% fee on ad exchange transactions for over a decade while competitors charged approximately half that amount. The complaint alleges this elevated pricing was sustained not through competitive merit but through exclusionary practices that prevented meaningful price competition.
The AdMeld Acquisition
When publishers began using technology to route their inventory to multiple ad exchanges simultaneously (a practice called “yield management” that threatened Google’s control), Google acquired AdMeld, a leading yield management platform, in 2011. According to the complaint, Google’s primary motivation was not to use AdMeld’s technology but to eliminate a competitive threat. After the acquisition, Google reportedly killed AdMeld’s yield management tools that helped publishers work with competing ad exchanges.
Responding to Header Bidding
The complaint describes how the advertising industry attempted to work around Google’s restrictions by developing “header bidding,” a technology that allowed publishers to solicit bids from multiple ad exchanges before calling Google’s ad server. This threatened to restore competition to digital advertising by giving all exchanges fair access to publisher inventory.
Google’s response, according to the complaint, was swift and multifaceted. Among the most striking allegations is the description of Project Poirot, a program that systematically manipulated advertiser bids to disadvantage competing ad exchanges.
How Project Poirot Worked
According to the complaint, Project Poirot worked by secretly lowering the bids that Google’s DV360 platform submitted to rival ad exchanges that used header bidding. Google reportedly reduced advertiser bids by 10% to 40% initially, and later by as much as 90% for some exchanges. Because Google’s own ad exchange did not participate in header bidding, bids to AdX were not decreased, even when DV360 bid on the same impression through both a rival exchange and Google’s exchange.
The complaint alleges that this manipulation virtually ensured that Google’s ad exchange would win auctions by virtue of deliberately decreased bids supplied to rivals for identical inventory. Google reportedly launched Project Poirot in July 2017, automatically enrolling over 99% of advertising campaigns without providing advertisers meaningful information about the program or an opportunity to opt out.
The financial impact was substantial. According to the complaint, Project Poirot shifted approximately $200 million in advertiser spending away from rival ad exchanges and toward Google’s exchange. Subjected to Google’s 20% revenue share fee, this resulted in an additional $40 million in profit for Google.
The Cost to Advertisers and Publishers
The complaint details how Google’s internal analysis found that Project Poirot would reduce publisher display revenue from DV360 by over 10%. The total number of impressions DV360 purchased would drop by almost 5%. Google allegedly recognized that some advertisers would no longer be able to buy certain impressions only offered on rival exchanges because Poirot reduced their bids below publishers’ minimum prices, preventing these advertisers from spending their full budgets and leaving some ad inventory unfilled.
Despite these harms, the complaint alleges that Google continued and expanded the program. The systematic drop in bid prices reduced the competitiveness of header bidding auctions, which lowered the win rates of exchanges relying on header bidding. Google’s ad exchange win rate increased even though Google had made no improvements to its exchange, offered no additional benefits to publishers, and reduced advertisers’ reach without their knowledge.
Additional Anticompetitive Tactics
Dynamic Revenue Share
The complaint describes how Google manipulated the fees it charged publishers without their knowledge to ensure more high-value transactions flowed through its ad exchange. Through a program called Dynamic Revenue Share, Google allegedly adjusted its fee structure on a publisher-by-publisher basis to make its exchange appear more competitive than it actually was, preventing publishers from making informed choices about which ad exchanges offered the best value.
Unified Pricing Rules
According to the complaint, Google introduced so-called Unified Pricing Rules that stripped publishers of their ability to set different price floors for different ad exchanges. This prevented publishers from offering preferred pricing to exchanges that charged lower fees, forcing all transactions through the same pricing structure regardless of the exchange’s value proposition. The complaint alleges this change was designed to eliminate one of the last remaining ways publishers could direct valuable inventory to exchanges that charged less than Google’s 20% fee.
Project Bell
The complaint describes Project Bell, through which Google reportedly lowered advertiser bids to publishers who partnered with competing exchanges. This created a penalty mechanism for publishers who attempted to work with Google’s rivals, according to the allegations.
Blocking Header Bidding on Accelerated Mobile Pages
When publishers increasingly adopted Accelerated Mobile Pages (AMP), a Google-developed format for fast-loading mobile content, Google reportedly blocked the use of standard header bidding on AMP pages. Publishers using AMP could only access competing exchanges through Google’s own “Open Bidding” system, which gave Google control over how and when competitors could bid on publisher inventory.
The Cumulative Impact
The complaint argues that Google’s conduct consists of a series of interrelated and interdependent actions with cumulative and synergistic anticompetitive effects. The government alleges that the full scope and effect of these practices could not be fully recognized in real time by anyone outside of Google.
Higher Costs, Reduced Innovation
According to the complaint, Google’s overarching goal has been to force as many transactions as possible (especially high-value transactions) to flow through its own advertising technology products, with Google taking a cut at each step. The focal point has been Google’s ad exchange, where it has consistently charged around 20% for open auction transactions since 2009 while rivals charged only a fraction of that amount.
The complaint cites Google’s own documents admitting that ad exchange technology largely became commoditized years ago, and that without Google’s ability to build and defend a protective moat around its products, competition would have driven prices down by as much as 75% for most transactions. Instead, Google has allegedly succeeded in defending supra-competitive prices while maintaining and even growing its market share.
Harm to Publishers and the Open Internet
The revenue share fees Google charges come directly out of advertisers’ budgets and ultimately out of publishers’ revenues. According to the complaint, this means advertisers can buy fewer ad impressions at the prices publishers are willing to sell, less advertiser spending reaches the publishers that internet users rely upon for content, and ultimately fewer publishers can offer internet users content without subscriptions, paywalls, or alternative monetization methods.
Stifled Competition and Reduced Choice
By hamstringing rivals’ abilities to compete on merit, the complaint alleges that Google’s conduct has stifled innovation and limited publisher and advertiser choice. The harm extends to internet users who have access to less free content because publishers receive fewer advertising dollars due to higher technology fees and less efficient advertising matches.
Market Power and Dominance
The complaint alleges that Google holds monopoly power in three distinct markets. These include publisher ad server software, ad exchanges, and advertiser ad networks. In publisher ad servers, Google reportedly holds approximately 90% market share. In ad exchanges, the complaint alleges Google holds between 50% and 70% of the market. This dominant position across multiple levels of the advertising technology stack gives Google unique ability to manipulate auctions, protect its position, hinder rivals, and work against its own customers’ interests, according to the allegations.
Barriers to Entry and Exit
The complaint describes how Google’s anticompetitive behavior has raised barriers to entry to artificially high levels, forced key competitors to abandon the market for advertising technology tools, dissuaded potential competitors from entering, and left Google’s few remaining competitors marginalized and unfairly disadvantaged. The government alleges that Google has prevented the free market from functioning fairly to support the interests of the advertisers and publishers who make today’s internet possible.
What This Means for Advertisers
For businesses that have purchased Google advertising services, the complaint provides detailed allegations of how Google’s monopolistic conduct resulted in higher costs and reduced options. The allegations describe systematic practices designed to ensure advertisers paid more than they would in a competitive market, often without their knowledge or consent.
The complaint alleges that Google manipulated advertiser bids, restricted access to competing advertising channels, prevented advertisers from reaching certain audiences available only on rival platforms, and extracted supra-competitive fees at multiple points in the transaction process. These practices, according to the government, harmed advertisers by increasing costs, reducing reach, and limiting choice.
The Path Forward
The Department of Justice brought this action to halt Google’s alleged anticompetitive scheme, unwind Google’s monopolistic grip on the market, and restore competition to digital advertising. The complaint seeks both injunctive relief to prevent continued anticompetitive conduct and structural relief to address Google’s alleged monopoly power across the advertising technology stack.
For individual advertisers, the complaint’s detailed allegations provide a factual foundation for understanding how Google’s conduct may have affected their advertising spending. The extensive documentation of Google’s internal communications, strategic decisions, and market impact offers insight into practices that allegedly cost advertisers billions of dollars over the past two decades.
Legal Claims
The complaint alleges violations of Sections 1 and 2 of the Sherman Antitrust Act. Specifically, the government alleges that Google has monopolized and attempted to monopolize publisher ad server software, ad exchanges, and advertiser ad networks. The complaint also alleges that Google has engaged in unlawful tying arrangements by conditioning access to its publisher ad server on the use of its ad exchange, and by conditioning access to advertiser demand on the use of its ad exchange.
The Sherman Act provides for both government enforcement actions like this complaint and private claims by injured parties seeking damages for antitrust violations.
Disclaimer: This summary is based on allegations contained in the Department of Justice complaint filed January 24, 2023, in the U.S. District Court for the Eastern District of Virginia. This summary is provided for informational purposes only and does not constitute legal advice. Companies considering potential claims should consult qualified legal counsel.