Retention

Separate the two churns first

They have nothing in common but the outcome, and conflating them wastes effort:

• Involuntary — payment failed. Often a large share of total churn, entirely mechanical, and the cheapest thing to fix in the whole business.
• Voluntary — they chose to leave.

Fix involuntary first. Card retries on a sensible schedule, dunning emails that reach a human, pre-expiry notification, and a grace period that does not immediately cut off access. This is recoverable revenue sitting untouched in most companies.

Diagnosing voluntary churn

Ask when the decision was actually made. It is almost never at cancellation — it is weeks earlier, at a failed expectation, an unresolved support issue, or a champion leaving.