Earlier this week, a new federal antitrust trial with explosive implications began. Ultimately, it will define how the policy world responds to the economic dominance of Big Tech. Only a month ago, Google was found guilty of illegally operating a monopoly over internet searching in the biggest technology competition case in two decades. That trial has now moved onto the remedy phase, with Judge Amit Mehta mulling whether to break up the company or impose behavioural remedies. But the new Google trial is even more significant, and goes to the heart of how giant platforms make money by dominating the global digital advertising market.

U.S. v. Google will examine in detail the complex systems that Google interposes between a publisher and an advertiser: systems that earn the corporation over $250 billion in revenue a year, and a $2 trillion market cap. Google has continued to grow as competition has been eliminated, doubling its revenue since 2018. For years, the AdTech business was forbiddingly complex, jargon-laden and difficult to understand, even for insiders, until academic Dina Srinivasan came up with the analogy of Wall Street stock exchanges.

What makes this trial so significant for the policy world? The electronic auctions being examined, that match buyers and sellers of digital advertising inventory, should be the purest free markets of all. Yet the middleman, Google, engineered them to ensure margins for itself of between 30-50%. When publishers and AdTech firms innovated to allow buyers and sellers to negotiate outside of Google’s systems, both sides of the transaction discovered they won, as the margin retained by the middleman had been diminished. This is how markets should work.