the technology used to buy and sell online display ads by restricting or eliminating the choices of its customers — both website publishers and advertisers — the
Ad exchanges control the auctions that match website publishers with advertisers. Google operates the largest exchange, known as AdX, later rebranded as Google Ad Manager. The justice department estimates that Google’s ad exchange controls 47% of the US market and 56% globally. Other popular ad exchanges include Pubmatic, Index Exchange and Magnite.
The company also said that many of the justice department’s contentions mischaracterise how the technology operates. Changes to the ad-tech platform were intended to improve the product, Google said. The limitations on rivals’ access were in place to reduce spam and ad fraud or help advertisers have better control over where ads appeared, the company said.
Popular websites testified that they felt compelled to use Google’s ad server product because of its exclusive access to Google Ads. Opening up the platform to allow more exchanges to bid on Google’s inventory required a huge lift from the company’s internal engineering teams to work through others’ problems with quality, testified Nirmal Jayaram, a Google engineer who worked on the company’s advertising tools for marketers.Before 2015, online display ads were sold using a “waterfall” method. A website’s ad server would ask each advertising exchange for bids sequentially.
Google said the DOJ’s descriptions of how the ad server worked mischaracterise the technology and that it was technically possible for websites to move another exchange in front of Google’s AdX in the waterfall. Few publishers used this technique, the company said, because they wanted to seek bids from the advertisers who had already chosen to work with Google.
DOJ expert Abrantes-Metz said Google’s purchase of AdMeld was a classic “killer acquisition” — buying a potential rival and deprecating the features that threatened its own product. Weintraub estimated that Google’s last look advantage increased the amount of ad spend on its platform by $473-million/year.