AppsFlyer has released data on the fourth anniversary of Apple’s App Tracking Transparency (ATT) framework, showing a transformed landscape where privacy and performance are no longer seen as competing priorities. Four years after ATT’s introduction, the industry appears to have transformed what was once viewed as a limitation into a foundation for more transparent, consent-based relationships with users.

Since ATT’s introduction in April 2021, the mobile ecosystem has evolved, with opt-in rates climbing steadily as both users and marketers have adapted to the privacy-first paradigm. AppsFlyer’s latest analysis reveals the current state of this maturing market.

User Opt-in rates continue to grow

The data shows growing user confidence. Globally, 50 per cent of users now consent to tracking, a significant 10 per cent increase since ATT’s initial rollout. This trend suggests that when users understand the value exchange behind data sharing, many are willing to participate in the advertising ecosystem.

“Our data reflects a maturing relationship between apps and their users,” says Roy Yanai, VP Product at AppsFlyer. “We’re seeing that transparency doesn’t necessarily reduce participation – it transforms it into an active choice rather than a passive default. Our research clearly shows that marketers can achieve effective attribution even in a privacy-centric environment by implementing a comprehensive measurement strategy. This includes optimising when and how the ATT prompt is presented to users, leveraging privacy-friendly aggregated measurement frameworks, implementing SKAdNetwork effectively, and utilising incrementality testing to identify true marketing impact. The most successful advertisers have embraced these approaches rather than seeing privacy requirements as obstacles.”

European markets, recently at the centre of regulatory attention, show particularly interesting patterns. France now reports an average opt-in rate just under 51 per cent, while Germany stands at 47 per cent – both representing significant portions of users who choose to participate when given clear information and control.

iOS Ad Spend shows strong growth

A clear indicator of market stabilisation comes from advertising spending patterns. iOS ad spend increased by 26 per cent from 2023 to 2024 – significantly outpacing Android’s 10 per cent growth in the same period. This increased confidence has translated to expanded campaigns, with 42 per cent of apps increasing their iOS ad investments between Q1 2024 and Q1 2025.

This spending shift reflects advertisers’ growing mastery of privacy-centric measurement approaches and their willingness to invest where they can demonstrate reliable returns, even in a more privacy-protected environment.

Privacy and performance finding balance

The data suggests a reconciliation between privacy protections and market performance, with non-organic installs on iOS growing by 29 per cent year-over-year compared to 21 per cent on Android. Meanwhile, developer adoption of ATT continues to climb, up 4 per cent in 2024 compared to 2023, and 71 per cent higher than in 2021.

These trends align with the recent regulatory developments in France and Germany, where authorities have emphasised that user privacy and fair competition must work in tandem rather than opposition.

“The rulings in France and Germany provide an important signal that user privacy and fair competition must go hand in hand,” commented Emilie Kuijt, DPO at AppsFlyer. “The advertising ecosystem needs both robust privacy protections and a level playing field for all. While this decision is unlikely to prompt a full rollback of Apple’s ATT framework across Europe, it does show growing regulatory momentum around platform power with several other European investigations still pending. If we look at what happened with third-party app stores, Apple complied with regulatory demands – but in a way that preserved its market position. We may see something similar here. Ultimately, these regulatory decisions will spark broader scrutiny across the EU, and perhaps, smarter design choices around privacy that don’t come at the expense of fair competition. It’s a reminder that consumer trust and a healthy digital economy aren’t mutually exclusive – and that both need to be protected.”