Organic share of new activated users

• Metric

  Cadence-matched cohort retention

  cohort retention at the natural cadence

  Share of a sign-up or activation cohort that does the value event in a later bracket matched to the product's natural cadence (for example week 4 or week 8). Read by segment for curve shape and across cohorts for stacking.

• Metric

  Cost per activated user

  acquisition cost per user who reaches value

  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.

• Metric

  PMF survey score ("very disappointed" share)

  must-have share

  Share of recent core users who would be very disappointed if they could no longer use the product, read per segment. Directional from about 40 responses. The 40% line is a heuristic, not a statistical cut-off.

• Metric

  Habitual-user rate

  share at the devoted cadence

  Share of activated users who meet the route's devoted cadence in the read week (week 8 by default). Compared with a 5% bar that is Hooked's rule of thumb, not a scientific cut-off, and read on the habit horizon.

• Metric

  Viral coefficient (K)

  new users each user brings

  Invites (or shares) per active user multiplied by the share of invites that become activated users. K near zero while users love the product means fans exist but have no path to share.

• Metric

  Promoter-to-referral rate

  share of promoters who actually refer someone

  Share of customers who score as promoters and go on to refer at least one new customer. A Recall & Trust headline metric: stated loyalty turned into behavior.

Sources

• How Superhuman built an engine to find product-market fit · First Round Review (Rahul Vohra), 2018

  BDatasetBenchmark confidence B. A reputable dataset.

Book content is paraphrased, never quoted at length. Last verified October 24, 2026.