The gap between signup completion and first product value event. When conversion rate rises but activation rate falls, the majority of acquired users never become retained users.
Every non-activating user generates full acquisition cost with zero LTV contribution. The economics of growth deteriorate invisibly while the conversion dashboard reads green.
CAC reporting. Effective cost per activated user is substantially higher than blended CAC. Day 7 and Day 30 retention curves collapse for non-activating cohorts.
Mobile conversion rate rising alongside a declining activation rate particularly in the weeks following a friction-reduction initiative.