Barred From Stalking Us Across the Internet, Returns for Some Advertisers Plummet

UCLA Anderson Review covers research on Apple’s App Tracking Transparency (ATT) policy and its impact on digital advertising. The article discusses the forthcoming Management Science paper by Guy Aridor (Northwestern), Yeon-Koo Che (Columbia), Brett Hollenbeck (UCLA Anderson), Maximilian Kaiser (Hamburg University), and Daniel McCarthy (University of Maryland) titled ‘Evaluating the Impact of Privacy Regulation on E-commerce Firms: Evidence from Apple’s App Tracking Transparency.’ Key findings include that since April 2021, approximately 80-85% of Apple users have rejected app tracking, with small e-commerce businesses experiencing the steepest losses—revenue growth declined 37% relative to Meta customers with more diverse advertising budgets. The research reveals that small firms relied heavily on Meta for traffic (averaging 60% versus 30% for larger companies) and that Google’s market share expanded while Meta’s dropped by 4.4% following ATT implementation, primarily due to Google’s broader ecosystem enabling continued user tracking across multiple services.