Post-IDFA Alliance data: ad spending on Android is up ~21% after Apple's ATT changes, iOS spending drops ~3%; 63.5% to 83.2% of iOS users opt out of tracking
Dean Takahashi / VentureBeat :
Context & Ripple Effects
Apple set this up a year in advance when it announced the Identifier for Advertisers would flip from opt-out to opt-in with iOS 14 — a change framed as a user-privacy win and a marketer loss. In January, [[a:962478|Google warned developers the change would cut visibility into app-install metrics and skew bidding]] on iOS ads, effectively flagging where budgets would go instead.
The Post-IDFA Alliance data is the first broad readout of that warning: Android ad spending up roughly 21% since the ATT changes took effect, iOS down about 3%, and 63.5% to 83.2% of iPhone users declining tracking. That opt-out range confirms what Apple bet on — consent rates too low to sustain identifier-based targeting at scale.
First-order effects
- Advertisers are redirecting budget from iOS to Android in real time, since ATT makes most iOS impressions unmeasurable for attribution and retargeting.
- Marketers buying Facebook and other tracked campaigns against iOS audiences lose targeting precision immediately, because the vast majority of opted-out users can't be matched to an identifier.
Second-order effects
- Google becomes the default beneficiary of the reallocation — Android inherits demand that Apple's platform can no longer price or attribute, strengthening its position in mobile ad auctions.
- Measurement firms like Tenjin turn into the arbiters of the shift, as advertisers rely on third-party spend data rather than Apple-supplied identifiers to decide where dollars go.
Third-order effects
- Mobile advertising splits into two regimes: consent-based ecosystems where opt-in rates cap addressable inventory, and platforms controlling both the OS and the identity layer — pushing the industry toward contextual and first-party-data targeting regardless of which platform wins any given quarter.
The trend: App-tracking consent requirements are redrawing the mobile ad market along OS lines, shifting spend toward whichever platform still controls usable user identity.