Growth
The growth marketer's guide to measuring real install lift
Incrementality is a word that's been beaten into mush. Here's a working definition, a measurement design, and the three places your numbers are lying.
ARAnya RousselHead of ProductMar 4, 2026·7 min read
Every growth team can tell you their cost per install. Most can tell you their attributed ROAS. Far fewer can answer the question 'which of those installs would have happened anyway?' — and that is the question your CFO is actually asking.
A working definition of lift
Install lift is the difference between attributed installs in a treated cohort and modeled organic baseline in an untreated cohort, measured during an identical time window with identical seasonality.
If you can't articulate the untreated cohort and the time window, you do not have a lift number. You have a directional comfort blanket.
Three places your numbers are lying
- You're attributing organic search installs to brand campaigns. Brand search is the worst offender — set up a holdout, not a regression.
- You're double-counting between MMP and SKAN. Run them in parallel, but pick one for headline KPIs.
- You're conflating install with first event. An install that doesn't open the app twice is not a customer.
“The most honest number on the growth team's slide is usually the one with the smallest cohort.”
Tagged#Growth#Incrementality#Measurement