90-DAY RETENTION
20-40%
The percentage of a cohort that stays indefinitely (the flat tail).
FLAT TAIL
Approaching zero means no fit.
ORGANIC REFERRAL
15%+
The share of new signups coming from word-of-mouth or unattributed direct.
MARKET PULL
コスト-free user acquisition.
EXPANSION (NRR)
110%+
Net Revenue Retention proving customers spend more over time.
STICKINESS
Product becomes indispensable.