Churn
The attrition rate measuring the proportion of customers or revenue lost over a given period. Logo churn counts cancelled contracts; revenue churn measures lost MRR or ARR. Negative churn means expansion revenue exceeds losses.
In practice
A healthy B2B SaaS targets annual revenue churn below 5-8%. Above 15%, each customer cohort erodes too fast for growth to remain viable without aggressive new acquisition. Churn is predictable: early warning signals — declining usage, unresolved tickets, changing contacts — typically appear 60-90 days before cancellation. A customer success programme that acts on these signals can reduce churn by 30-50% over twelve months.