The Death of CPI: Why Cost-Per-Install Is the Wrong Metric in 2026

By Intent+ Team · May 7, 2026 · 11 min read · 2,100 words

Optimising for installs is killing your iOS ROAS. This is a defence of the unpopular position — backed by data from 200 Apple Ads account audits — and a clear argument for what to measure instead.

The Case Against CPI Optimisation

65% of iOS accounts in our 2025–2026 audit cohort were still primarily optimising against an install-based event. Their median ROAS: 0.6×. CPI optimisation selects for users who install — not users who pay.

How SKAN 4 Changed the Optimisation Equation

SKAN 4 allows bidding against post-install conversion events across three postback windows. The install event is now the least informative signal you could give Apple's algorithm to optimise against.

What to Optimise Against Instead

Optimise against the latest revenue-bearing event you have enough SKAN 4 signal on — typically D7 purchase, D7 subscription start, or a high-value engagement event mapped to your conversion value schema.

The Transition Playbook

How to migrate from CPI optimisation to ROAS-event optimisation without blowing up spend during the transition period. The sequencing matters: CV mapping first, then event testing, then bid strategy shift.

Frequently Asked Questions

Is CPI still a useful metric at all, what SKAN 4 events to use, how long the transition takes, and how to get buy-in from stakeholders still attached to install metrics.