“You have greater surface area or greater reach earlier on in the funnel because more users are still around. That's a big lever on how much impact you'll drive with any particular notification — the size of your target audience that's addressable.”

Reach is biggest at the top of the funnel — optimize there first

Optimizing the last step of a funnel feels sophisticated but rarely pays. The first or second touchpoint matters more because cohorts haven't decayed yet — same logic applies to which lifecycle moments deserve investment. Pick the high-reach moments and invest relevance there.