The news: The EU fined Google $3.5 billion for abusing its dominance in digital advertising. Regulators say Google used its control of the ad tech supply chain to shut out rivals, squeeze publishers, and limit advertiser choice, per The New York Times.

It’s the fourth time Brussels has hit Google with a multibillion-dollar penalty. Previous fines include €4.34 billion ($5 billion) in 2018 over Android, €2.42 billion ($2.7 billion) in 2017 for favoring its shopping service, and €1.49 billion ($1.7 billion) in 2019 for AdSense restrictions. Together, the cases show Europe’s intensifying campaign against Big Tech.

Why it’s worth watching: The money may matter less than the precedent. Google has 60 days to propose remedies and vowed to appeal. “The ruling concerning our ad tech services is erroneous … it will adversely affect thousands of European businesses,” said Lee-Anne Mulholland, Google’s global head of regulatory affairs.

For marketers, the case could crack open the black box of ad pricing. More transparency and competition in ad tech may drive down costs—at least in the EU.

Across the pond: The EU’s tough stance against antitrust actions contrasts with a more cautious approach in the US.

• While US regulators have ramped up scrutiny, they’ve stopped short of issuing fines of this scale.
• President Donald Trump previously threatened to retaliate against any “discriminatory (or) disproportionate” penalties on US companies from foreign governments, which could raise geopolitical tensions around tech regulation.

The bigger picture: The fine lands as Google’s grip on the search ad market is already slipping. We forecast Google’s US search ad share will drop below 50% in 2026, falling from 54.9% in 2022 to 48.5% in 2027. Amazon is the main beneficiary, projected to hit 24.2% by 2027, while Microsoft climbs to 6.4%.

• That decline makes the EU ruling more dangerous for Google, by piling regulatory risk on top of competitive threats. Google’s dual role—running both the ad exchange and selling its own inventory—sits at the heart of the case. 
• Regulators argue this lets Google view rival pricing and steer advertisers to its own products, a conflict of interest that cuts to the core of online advertising.

Google faced similar antitrust rulings from a US District Court and the Department of Justice (DOJ); it also received a €325 million fine ($356 million) last week for two breaches of French advertising and cookie laws, indicating global regulatory scrutiny is intensifying.

Our take: Google can still cut deals to soften compliance terms, but the trend points toward tougher oversight and fewer compromises. For advertisers, that means preparing for a future where Google’s ad stack may be pried open—whether by negotiation or by mandate.