Churn
Also called Churn Rate and Attrition
The rate at which customers stop paying you over a period. Revenue churn measures the money that leaves, customer churn measures the logos. Its opposite, retention, is what keeps a business alive.
Monthly churn = customers lost in the month / customers at the start of the month
Why it matters
High churn means you are filling a leaky bucket: every new customer just replaces one you lost. It caps how big you can grow and is often the clearest signal that you do not yet have product-market fit.
For example
A SaaS product starts the month with 1,000 customers and loses 50, a 5 percent monthly churn that quietly caps how fast it can grow.
Go deeper
Related terms
Also in Starting Up
See how founders actually handle this on Money, pricing and metrics, part of the Starting Up hub.
eChai Partner Brands
