Google submitted an updated filing in its antitrust trial on Tuesday, emphasizing that its ad platform is open for publishers to mix and match with ad tech providers outside of Google to sell ad space. If Google’s ad tech is indeed as open as the company says, then the judge could determine it’s not operating a monopoly, but ad tech rivals say it’s still unclear that publishers can reasonably participate in robust digital ad markets outside of Google's tools.

The updated documents from Google were submitted as part of its antitrust trial that was heard in September in U.S. District Court for the Eastern District of Virginia, presided over by Judge Leonie Brinkema.

Both sides submitted final “proposed findings of facts” that rehashed key points from the three-week trial. In its 600-plus page filing, Google continued to argue that publishers that use Google Ad Manager to control their online ad inventory are free to run other ad tech to fill ad space, too. Google also argued publishers could use outside ad tech to receive advertising demand from Google, meaning publishers were not forced to use Google Ad Manager to benefit from Google’s lucrative source of advertising. 

Buy side and sell side

A core argument made by the U.S. Department of Justice was that publishers were locked into using Google Ad Manager, which allegedly accounts for almost 90% of the market providing ad tools to websites online. The DOJ has claimed that Google’s power on the sell side of the market, through Google Ad Manager’s relationship with publishers, and its weight on the ad side of the market, through Google Ads’ advertising demand, makes it a monopolist.

Google has said that its business model aligns with other players in ad tech that also have hooks on the buy and sell sides, and that it faces formidable competition from rivals such as Amazon, Meta, TikTok, The Trade Desk, and other ad tech players. Google also argued that it is not beholden to build its ad platform to benefit outside parties.

“Plaintiffs ignore numerous ways that Google has enabled publishers to interoperate with rivals and sell ad inventory without the need to use one or more Google tools,” Google stated in its “proposed finding of facts” filing Tuesday. “For example, Google made it possible for publishers to use its [DoubleClick for Publishers] tool to offer all of their impressions to Amazon’s and Prebid’s header-bidding offerings, through which publishers reach over 100 competing exchanges. Google also built Open Bidding, a competitive alternative to header bidding that enables publishers to sell inventory through approximately 25 rival exchanges within Google’s platform.”

Google was addressing the claim that online publishers are shackled to Google’s ecosystem through mechanisms such as needing to run Google Ad Manager, formerly DoubleClick for Publishers, to tap into Google’s pool of advertising dollars that comes through AdX, the ad exchange. The interoperability and ability for publishers to tailor how they use Google Ad Manager are key points of contention in the case.

The outcome of the case will likely determine the future of Google’s ad tech business, an industry the search giant helped develop ever since it bought DoubleClick for $3.1 billion in 2008. The DOJ has suggested breaking up Google’s ad tech business.

The antitrust trial has exposed Google to industry scrutiny, revealing internal communications that gave advertisers reasons to question the company. For instance, Google was accused of harming advertisers by raising pricing on ads to boost publisher interest in DoubleClick for Publishers. There also were internal documents that purported to show how Google leveraged a rebate program to incentivize agencies to spend on its platform.

The argument about interoperability with independent ad tech tools is a sore spot among some ad tech providers. Google has been accused of making it exceedingly difficult for publishers to avoid using Google’s AdX ad exchange in Google Ad Manager to fill their ad space.

“The argument falls flat,” said one ad tech executive on the supply side, who spoke on condition of anonymity. “AdX is bundled with Google search … turning this off turns off about half the ad spend most publishers see today from programmatic. So turning it off, while technically possible, would put publishers out of business. And herein lies the problem. The effective bundle of GAM and AdX and search demand is potent and subject to the scrutiny the case in question has brought.”

More: Google’s owner is one of the largest U.S. advertisers

Google was not immediately available for comment for this story. Google has maintained that AdX is not bundled with search demand, another lucrative pool of ad dollars, and that Google doesn’t require publishers or advertisers to use its whole tech stack for their operations. In its filing, Google made this argument: “A publisher can use [DoubleClick for Publishers] in conjunction with header bidding and/or Open Bidding to sell ‘every single’ impression without ever using AdX.”

Another Google critic, an ad tech executive who also spoke on condition of anonymity, disagreed with Google’s claim, and said: “No you can’t use GAM without AdX.”

Google stated that advertisers also have flexibility using its ad tools: “Google’s [Display and Video 360] allows them to bid into over 100 third-party exchanges, and those advertisers can choose to never purchase on AdX,” Google wrote.

The two sides, Google and the DOJ, are set to hold in-person closing arguments on Nov. 25 to wrap up the trial.