Google loses first round in Canadian advertising tech case

Tashi Farmilo

The Canadian government’s competition watchdog announced on March 4 that Canada's Competition Tribunal has rejected a bid by Google to shut down a federal case against it, allowing the watchdog to proceed with what could become one of the most significant antitrust actions in the country's history.

The case, brought by the Competition Bureau in November 2024, accuses Google of illegally dominating the behind-the-scenes technology that determines which advertisements Canadians see when they browse the internet, and how much advertisers and publishers pay for those ads. When a person visits a website and an advertisement appears, a rapid-fire automated auction takes place in milliseconds to decide which ad is shown. Google owns the dominant tools on all sides of that transaction: the software used by websites to sell ad space, the exchange where those auctions happen and the platforms used by advertisers to place bids. The bureau found that Google holds a market share of roughly 90 per cent in publisher ad servers, 70 per cent in advertiser networks and about 50 to 60 per cent in the auction exchanges themselves.

The bureau alleges that Google used its control over these multiple links in the chain to squeeze out competitors, slow innovation, push up costs for advertisers and reduce the revenue flowing to publishers, including Canadian news outlets and websites that depend on advertising income.

To put a stop to that, the bureau is asking the tribunal to order Google to sell off two of its key products in this space: DoubleClick for Publishers, the tool websites use to manage and sell their ad space, and AdX, the exchange where ad auctions are conducted.

Google attempted to block the case before it reached that stage by raising a constitutional challenge, arguing that a right had been violated. The tribunal rejected that argument, affirming its authority to impose financial penalties designed to deter anti-competitive behaviour. Jeanne Pratt, the interim Commissioner of Competition, called the ruling a reaffirmation of the tribunal's powers and said the bureau's case would continue.

Google has maintained that the online advertising market is highly competitive and that the bureau's complaint ignores the wide range of choices available to advertisers and publishers.

The Canadian proceedings are part of a wider global reckoning with Google's advertising business. In April 2025, a United States federal court ruled that Google had violated American antitrust law by maintaining illegal monopolies in the same two markets targeted by the Canadian bureau. That American case has since moved into a remedies phase, with a ruling expected this year. European regulators are watching those American proceedings closely before advancing their own parallel case.

Any final ruling in Canada, including the question of financial penalties or forced sales of Google's products, rests with the Competition Tribunal.