Net revenue retention (NRR)

Revenue this period from last period's customers, including upgrades and downgrades, as a percentage.

Example

$100k of cohort revenue becomes $115k a year later after churn and upsells — 115% NRR.

Above 100% means the company grows even with zero new customers. It is the metric that most separates good SaaS from average SaaS.

Churn — The rate at which customers or revenue leave over a period.
Retention — The share of customers still active after a given period. The inverse of churn, and usually the more useful way round.
MRR (Monthly Recurring Revenue) — Predictable revenue that repeats every month from subscriptions or contracts.

Retention, referral and growth loops — A funnel needs constant refilling. A loop reinvests its own output. The difference decides whether growth compounds. (12 min)
Cohort analysis — Group users by when they joined and follow each group. It is the only way to tell real improvement from a growing pile of signups. (12 min)
MRR and ARR — Recurring revenue is the number investors care about most — and the one founders most often calculate wrongly. (10 min)