In-app vs web inventory: same DSP, in-app converted 2.3x better — here's why

In-app vs web inventory: same DSP, in-app converted 2.3x better — here's why
A subscription app split $60k evenly across in-app and mobile-web inventory through the same DSP, identical creatives and audiences.

In-app drove 2.3x the trial starts at a 19% lower CPA. The reason wasn't 'better users' — mobile web lost 38% of clicks to Safari ITP cookie loss and slow LP loads before the SDK ever fired.

When they added a deferred deep link, in-app's edge widened further (web can't deep-link into an installed app reliably).

✓ Deferred deep linking is the real in-app advantage, not audience
✓ SDK-level tracking sidesteps ITP entirely
✗ In-app inventory is pricier per impression (won on conversion, not CPM)
✗ Brand-safety controls are thinner in some in-app exchanges

Verdict: buy in-app for installed-app actions, web for net-new reach.
Best for: app marketers comparing channel economics.