Metric
Cost per activated user
Acquisition spend divided by the new users it brought who reached first value. Judging channels on activated users instead of sign-ups keeps spend away from traffic that never sticks.
Plain label: acquisition cost per user who reaches valueAlso known as: CAC per activated user, cost per activation
Read per channel and per campaign. LTV:CAC of at least 3 and CAC payback under about 12 months are common SaaS rules of thumb, not empirical laws (benchmark confidence C); compute lifetime value from cohort revenue curves, not from 1/churn, while cohorts are young.
Scaling paid acquisition is out of season until a segment retains; buying traffic into a leaking product only fills a leaky bucket.
Sources
Book content is paraphrased, never quoted at length. Last verified October 24, 2026.
Your product
Find the stage your product is stuck in
Gamify It reads your product, picks the one move that matters at its stage, and sizes the test to your traffic. Connecting is free; a Pro subscription starts it.