Churn

Subscribers leaving: expirations after a cancellation, refunds, failed billing that never recovers. Counted as event volume over a window (and as a rate against the base at the window's start). The subtlety is what not to count: a billing retry isn't churn yet, and a cancelled trial never paid to begin with.

The notification types that genuinely mean a paying subscriber is gone: EXPIRED (with a subtype saying why: VOLUNTARY, BILLING_RETRY, PRICE_INCREASE, PRODUCT_NOT_FOR_SALE), GRACE_PERIOD_EXPIRED, REFUND, and REVOKE for Family Sharing access that ended.

The three that look like churn and are not:

• ▸DID_CHANGE_RENEWAL_STATUS with AUTO_RENEW_DISABLED. That is intent. The subscriber keeps access, and keeps paying for it, until the period ends. The money stops at EXPIRED.
• ▸DID_FAIL_TO_RENEW. Billing failed; the subscription can still recover.
• ▸A trial that ended without converting. Nothing recurring was lost, because nothing recurring existed. That belongs to trial conversion, not churn.

Separating voluntary churn (they chose to leave) from involuntary churn (their card failed) matters because only one of the two is fixed by a better product.

See: How churn is counted →