Churn: customer attrition

Churn tracks the share of customers or subscriptions you lose—and it hits LTV directly.

Three columns—what churn measures, why it hits LTV, and how cohorts and win-back connect—with arrows from the customer base to retention.

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What it is

Measure it over a period as leavers versus starting base, or use cohort views. SaaS teams often split logo churn and revenue churn.

High churn consumes acquisition gains—you’re bailing a leaky bucket.

Segment exit reasons. Link them to onboarding, product, and support. Marketing joins win-back and retention plays.

Table 1. Definition and business context

Criterion	In short
Definition	Measure it over a period as leavers versus starting base, or use cohort views. SaaS teams often split logo churn and revenue churn.
Why businesses care	High churn consumes acquisition gains—you’re bailing a leaky bucket.
Effect when done right	Lowering churn usually lifts profit more than shaving CAC a little.

Table 2. Practice, ecosystem, and related terms

Area	What to consider
How to apply	Segment exit reasons. Link them to onboarding, product, and support.
Works with	It connects to email, product analytics, and NPS.
In the glossary	LTV: customer lifetime value, CAC: customer acquisition cost, Email marketing, CRM marketing

Lowering churn usually lifts profit more than shaving CAC a little.

It connects to email, product analytics, and NPS.