Google and the Department of Justice (DOJ) have made their final arguments in a crucial antitrust case that could shape the future of online advertising. In an Alexandria, Virginia courtroom, attorneys for both sides presented their closing statements to US District Court judge Leonie Brinkema, who is expected to rule on the case by the end of 2024.

The DOJ alleges that Google has used its suite of ad tech products, including Doubleclick For Publishers (DFP) and the AdX exchange, to strong-arm site owners and advertisers, thereby establishing a monopoly in the online ad market. Google, on the other hand, argues that it faces competition from other sources and should not be forced to cut deals with competitors.

One of the key points of contention in the case is the definition of the market in which Google operates. The government sees three separate ad markets that Google dominates: one for publisher ad servers, one for ad exchanges, and one for advertiser ad networks. Google, however, claims that there is a single, two-sided market of buyers and sellers for digital ads, putting it in competition with social media companies like Meta and TikTok.

The government has drawn parallels between this case and the 2018 Supreme Court precedent Ohio v. American Express, which considered whether a policy imposed by AmEx on merchants unfairly suppressed price competition. However, Judge Brinkema expressed skepticism about this comparison, suggesting that the facts of the two cases are distinct.

Google's counsel, Karen Dunn, argued that the company's products are already interoperable with other ad tech services, and requiring more interoperability by law would make Google's advertiser customer base into "community property." The DOJ countered that Google's refusal to deal with competitors is a key indicator of its monopoly power.

The case has also been marked by allegations that Google deliberately deleted chat messages that could have incriminated the company. Google has conceded that some deleted messages included substantive business discussions, but argues that most were simply casual conversations. The DOJ, however, wants Judge Brinkema to draw an adverse inference wherever she is in doubt about what the deleted messages said, assuming that they would have looked bad for Google's case.

Judge Brinkema's ruling in this case could have far-reaching implications for the online advertising industry, potentially forcing Google to make significant changes to its ad tech business. The outcome will be closely watched by industry observers and could set a precedent for future antitrust cases involving tech giants.

As the case moves forward, the tech industry will be waiting with bated breath to see how Judge Brinkema rules on the DOJ's allegations. Will Google be declared a monopolist, or will it emerge victorious? The answer will have significant implications for the future of online advertising and the balance of power in the tech industry.