PubMatic files antitrust lawsuit against Google over digital advertising monopoly

PubMatic has filed a comprehensive antitrust lawsuit against Google on September 8, 2025, alleging the search giant's monopolistic conduct caused substantial financial harm to the advertising exchange platform. The complaint, filed as Case No. 1:25-cv-1482 in the U.S. District Court for the Eastern District of Virginia, seeks monetary damages and injunctive relief following a federal court's determination that Google illegally monopolized critical digital advertising markets.

According to the 85-page filing, PubMatic contends Google's anticompetitive behavior severely limited the company's ability to compete in markets it helped create. The lawsuit follows Judge Leonie Brinkema's April 2025 ruling that Google "willfully engaged in a series of anticompetitive acts to acquire and maintain monopoly power in the publisher ad server and ad exchange markets for open-web display advertising."

Pioneering company seeks accountability

"For nearly two decades, PubMatic has delivered sustainable innovation and efficiency in digital advertising, empowering publishers to maximize their revenue and deliver quality content to users worldwide," said Rajeev Goel, PubMatic's co-founder and CEO, according to the complaint. "Google's systematic abuse of its vast resources and immense power has harmed our business and distorted a marketplace that should have rewarded innovation and fueled transparency and competition."

The complaint details how PubMatic transformed digital advertising through breakthrough technologies, including pioneering real-time bidding in 2008. "PubMatic conducted the first real-time transaction with another company, Invite Media," the lawsuit states, emphasizing the company's role in creating the foundation of modern programmatic advertising.

PubMatic describes its mission as providing publishers "something they had never had before: the ability to manage and optimize every impression, increase revenue, and gain unprecedented visibility and control over their inventory—all while maintaining independence and transparency."

Systematic market manipulation through acquisitions

The complaint alleges Google built its dominance through strategic acquisitions rather than innovation. "While the digital advertising industry was on a rapid upward trajectory, in part because of PubMatic's leadership and innovations, Google was conspiring behind the scenes to monopolize the industry," the filing states.

Google's approach differed fundamentally from PubMatic's organic development. "In contrast to PubMatic, rather than compete through innovation, Google purchased entities that already existed in each area of the ad tech stack," according to the lawsuit. The complaint notes Google paid $3.1 billion for DoubleClick in 2008, significantly above its internal valuation of $1.8-2.2 billion.

Internal Google documents reveal the strategic motivation behind the overpayment. The lawsuit quotes Google executives stating they "didn't buy [DoubleClick] [DFP] for the revenue (& growth) – [Google] bought it for enabling the [Ad] Exchange." Google recognized that losing "platform share" would mean "still be at a severe risk of being disintermediated" even if it built "the best GCN [AdWords] in the world."

Unfair advantages through technical manipulation

The complaint details Google's implementation of "First Look," which "required publishers using DFP to offer AdX a first right of refusal for each impression." This policy gave Google's exchange unfair priority over competitors. "AdX received a First Look at DFP impressions even if the publisher preferred other exchanges and wanted to rank them first," the lawsuit states.

Google later enhanced its advantages through "Last Look," which "gave AdX the ability to see competing exchanges' bids in an otherwise sealed auction before AdX would bid." The complaint explains this allowed AdX to "adjust its advertisers' bids to exceed the winning bid by just one cent and win the ad space."

The lawsuit describes how this unfair advantage harmed both publishers and competitors. "Without Last Look, AdX would have been required to bid on publishers' offerings without first seeing the winner of the header-bidding auction," resulting in higher publisher revenue. Instead, "AdX could artificially depress that revenue by adjusting its winning bid to exceed the bids of competing ad exchanges by just one cent."

Secret revenue manipulation program

PubMatic alleges Google operated a covert "Sell-Side Dynamic Revenue Share" program that manipulated auction outcomes. "SSDRS gave AdX another new, and secret, capability," the complaint states. "With SSDRS, AdX could manipulate its take rate from one auction to another."

The lawsuit provides a detailed example of this manipulation: "A publisher runs a header-bidding auction, and the winning bid is from PubMatic at $5.50. Because of Last Look, AdX knows it needs to bid $5.51 to win the auction, but the highest bid that AdX's advertisers... are willing to place for this advertising space is $6.00. If AdX extracts its standard 20% take rate, the highest bid AdX could place is $4.80. That would not beat PubMatic's bid, so PubMatic would win. But SSDRS enables AdX to steal that win."

Google concealed this program's true capabilities from the industry. "Google first introduced SSDRS in 2014, but did not disclose its existence until 2016," the complaint notes. Even then, "Google's announcement of SSDRS disclosed nothing about AdX's ability to manipulate its take rate for individual auctions."

Project Poirot's systematic bid reduction

The lawsuit describes Project Poirot as Google's systematic effort to reduce competitor success. "Under Project Poirot, Google would systematically and surreptitiously 'shade,' or reduce, the bids that DV360 submitted to competing advertising exchanges," according to the filing.

The impact proved substantial and immediate. "Beginning in 2017, all advertising campaigns that were run through DV360 were automatically opted into Project Poirot," the complaint states. "When it first launched, Project Poirot reduced DV360 bids placed with non-Google ad exchanges by 10% to 40%. In late 2018, Google revamped Project Poirot and released Project Poirot 2.0, which reduced DV360 bids placed with some rival exchanges by up to 90%."

PubMatic experienced direct financial harm from this manipulation. "During the months following Project Poirot's introduction, PubMatic suffered a decline in spending from DV360 of at least 30%, depriving PubMatic of millions of dollars of additional revenue," the lawsuit states.

Deceptive practices and concealment

The complaint alleges Google actively misled PubMatic and its customers about the causes of declining performance. When PubMatic contacted Google in August 2017 about reduced DV360 spending, "Google offered a vague response that the decline PubMatic was experiencing was 'due to filtration' by Google's 'AdSpam team'—in other words, the inventory on which the bids would be placed had been flagged as fraudulent or spam."

This explanation proved false, particularly given "the decline related to inventory being offered by several of PubMatic's major publisher customers, including eBay and AOL." When PubMatic pointed out these inconsistencies, "Google once again fell silent and ignored PubMatic's follow-ups in late 2017 and early 2018."

Even sophisticated customers faced Google's deception. The lawsuit describes how a major agency holding company discovered "despite AHC preferencing PubMatic's exchange within the DV360 platform, the vast majority of AHC's bids were going through AdX. AHC reported that number as 90%." When the agency contacted Google, the company "came up with a different excuse" each time rather than revealing Project Poirot's manipulation.

Unified Pricing Rules eliminate competition tools

Google's 2019 implementation of Unified Pricing Rules represented another anticompetitive measure. "Under UPR, Google 'prohibited publishers using DFP from setting higher floor prices for AdX than for other exchanges,'" the complaint states.

Publishers recognized this policy's true purpose. The lawsuit quotes Jana Meron of Business Insider telling Google that UPR "was built for Header Bidding NOT to exist." Similarly, Matthew Wheatland of the Daily Mail reported the "general trend is that CPM has decreased a lot since UPR," with AdX "monetising roughly 3x the amount of our inventory post UPR."

Substantial financial damages

The complaint documents extensive harm to PubMatic's business. "Between November 2015 and November 2016, PubMatic was forced to reduce its workforce by more than 40%. In the same time period, Pubmatic's revenue declined by approximately 8%," according to the lawsuit.

Project Poirot's impact proved particularly severe. "From 2017 to 2018, PubMatic's revenue declined by almost 20%," the filing states. "In 2018 and 2019 (when Project Poirot was active), PubMatic experienced an overall decline in its revenue growth rate. Many of its previously profitable customer accounts became unprofitable during this period, such that approximately 25% of PubMatic's customer accounts were not profitable."

The lawsuit emphasizes how Google's conduct prevented natural business development. "PubMatic would have been far more successful if not for Google's repeated monopolistic and illegal behavior," the complaint states. "Google's anticompetitive tactics impeded and undermined PubMatic's ability to grow, increase market share, and compete in the very fields that PubMatic helped create."

Industry-wide harm beyond PubMatic

The complaint describes broader market damage from Google's practices. "Google's dominance both deprived publishers and advertisers of the benefits of fair competition and caused real damage to consumers in the form of higher prices due to advertising cost increases, less diversity of content and voices, and less transparency," according to the filing.

PubMatic's CEO emphasized the broader implications: "Instead, anticompetitive practices limited monetization for publishers, raised costs for advertisers, and ultimately reduced choice for consumers."

Legal foundation and relief sought

The lawsuit builds on established findings from Judge Brinkema's ruling that Google "willfully engaged in a series of anticompetitive acts to acquire and maintain monopoly power in the publisher ad server and ad exchange markets for open-web display advertising." The court concluded that Google's conduct "substantially harmed Google's publisher customers, the competitive process, and, ultimately, consumers of information on the open web."

PubMatic seeks substantial monetary relief under federal antitrust law. "Based on and in light of the foregoing, PubMatic expects that its awardable damages in this case, once trebled pursuant the relevant antitrust laws, will reach into the billions," the complaint states.

The company requests the court "issuing an injunction prohibiting Google's anticompetitive conduct and mandating that Google take all necessary steps to cease such conduct and restore competition" along with "compensatory, consequential, and punitive (including treble) damages for all past, current, and future injuries directly and proximately caused to PubMatic by Google."

Timeline

• 2006: PubMatic founded to help publishers optimize ad revenue
• 2008: Google acquires DoubleClick for $3.1 billion, implementing First Look
• 2009: Google ties AdX to DFP and restricts AdWords to AdX
• 2014: Industry develops header bidding to counter Google's advantages
• 2015: Google introduces covert Sell-Side Dynamic Revenue Share
• 2017: Google launches Project Poirot to manipulate competitor bids
• 2019: Google implements Unified Pricing Rules
• January 2023: DOJ files antitrust lawsuit against Google
• April 17, 2025: Court rules Google monopolized ad tech markets
• August 4, 2025: OpenX files follow-on lawsuit
• August 29, 2025: Dotdash Meredith files comprehensive antitrust lawsuit
• September 8, 2025: PubMatic files Case No. 1:25-cv-1482 seeking damages

Summary

Who: PubMatic, Inc., an independent advertising technology company founded in 2006, filed the lawsuit against Google LLC. PubMatic operates an ad exchange platform serving publishers and advertisers globally, helping create real-time bidding technology that transformed digital advertising.

What: A comprehensive antitrust lawsuit alleging Google illegally monopolized publisher ad server and ad exchange markets through systematic anticompetitive conduct including unlawful tying arrangements, auction manipulation through First Look and Last Look policies, secret revenue manipulation via Sell-Side Dynamic Revenue Share, and systematic bid reduction through Project Poirot targeting competitors.

When: Filed September 8, 2025, as Case No. 1:25-cv-1482, following the April 17, 2025 federal court ruling that established Google violated antitrust laws by monopolizing digital advertising technology markets through exclusionary conduct spanning over fifteen years of systematic market manipulation.

Where: The U.S. District Court for the Eastern District of Virginia, the same court that ruled against Google in the government's antitrust action targeting worldwide monopolization of advertising technology markets affecting billions in annual transactions across global digital advertising infrastructure.

Why: PubMatic seeks to recover substantial damages reaching potentially billions when trebled under antitrust law, aiming to restore competitive conditions in digital advertising markets where Google's conduct prevented the company from reaching its full potential in markets it helped create while systematically harming publishers, advertisers, and consumers through reduced competition, innovation, and transparency.