Apple introduced its App Tracking Transparency policy in April, which forced apps to ask for permission before they tracked the behavior of users to serve them personalized ads.
Most users have opted out, leaving advertisers in the dark about how to target them. Advertisers have responded by cutting back their spending at Snap, Facebook, Twitter and YouTube and diverted their budgets elsewhere: in particular to Android phone users and to Apple’s own growing ad business.
Sheryl Sandberg, Facebook’s chief operating officer, has said the iPhone changes meant “the accuracy of our ads targeting decreased, which increased the cost of driving outcomes for our advertisers. And . . . measuring those outcomes became more difficult.”