It is worth separating from the churn rate, which is the measurement. Churn itself is an event with a cause, and causes fall into recognisable groups. Voluntary churn is a decision: the product stopped being worth it, the problem went away, a competitor was chosen, or nobody ever got value in the first place. Involuntary churn is mechanical — an expired card, a failed payment, an unanswered renewal email — and it is often a surprisingly large share of the total.
The distinction matters because the fixes are completely different and one of them is nearly free. Involuntary churn is solved with dunning emails, card-expiry warnings and retry logic, and recovering half of it typically takes an afternoon of setup. Voluntary churn requires understanding, which means asking. A one-question cancellation form and a short note to anyone who leaves will teach you more about your product than a month of feature planning. Early churn — people leaving in the first thirty days — is almost always an onboarding or expectation problem rather than a product one.
A concrete example: eighteen customers leave in a quarter. Seven cancelled after a failed payment nobody followed up on, six left within three weeks of signing up, and five had been with you over a year. That is three separate problems: a billing gap you can close this week, an onboarding gap, and genuine long-run product limits. The aggregate churn rate would have shown one number and none of that.