The Interface Playbook · The 2019 Play
The Interface
Every account on the modern internet starts at the same place: a sign-in sheet with a stack of buttons. For the iPhone’s first twelve years, those buttons belonged to Google and Facebook—and whoever owns a button on that sheet owns the identity graph behind it: who you are, where you log in, what you come back to. Apple owned the device, the store, and the screen. The door to the account layer it didn’t own at all.
The Rule
Announced at WWDC on June 3, 2019; in the App Store Review Guidelines by September 12, 2019: any app using a third-party or social login “must also offer Sign in with Apple as an equivalent option.” Existing apps had until April 2020, extended to June 30, 2020. Google fought for the search box with $20 billion a year; Facebook built a developer platform. Apple conscripted its distribution by policy—the only play in the playbook that shipped as a paragraph.
The Wrapper
The button came wrapped in a real benefit: tap it and Apple mints a random relay address, so the app can reach you while your inbox stays hidden. In one global restaurant chain’s iPhone app, 19.3% of new sign-ups arrived as relay addresses (AtData, 2021). Every one is an email the developer can’t match to an ad profile, and a login Google and Facebook never see at all. Like App Tracking Transparency, the privacy halo and the competitive weapon are the same feature.
The Quiet End
The state circled first: the House antitrust report in October 2020, then a DOJ probe of the sign-in rule reported in February 2021. On January 25, 2024, in the same announcement cycle as its EU Digital Markets Act compliance package, Apple quietly rewrote 4.8: apps now need “an equivalent privacy-focused login service”—criteria 9to5Mac read as a description of exactly one product. The requirement had stood for 1,596 days. No competitor ended it. The state, again, barely did.
The Tell
Apple has never published a Sign in with Apple number: not accounts, not sign-ins, not share. The only readings are external. Across Auth0’s login platform in March 2022, Apple’s button was already the #2 social login, at 14% of social sign-ins against Google’s 75%, and Okta’s own analysts credited the App Store requirement. That is the tell of the cheapest play on the board: when Apple wants an interface, it doesn’t build market share. It writes a rule.
End of the play
Plays explored: 1 of 14