Churn rate is the percentage of customers or revenue that stop using or paying for a product over a defined period (monthly, quarterly, annually). It is measured separately as customer churn (logos lost) and revenue churn (dollars lost), and treated as the inverse of retention. It is one of the two or three numbers that determine whether a subscription business compounds or quietly dies.
There are two distinct measurements that get conflated and should not be: customer churn is logos divided by logos at start of period; revenue churn is MRR (or ARR) lost divided by MRR at start of period. A SaaS business can have low customer churn and catastrophic revenue churn if it loses its biggest accounts; the inverse is true at the SMB tie...