“It's a good idea to just do some interviews with churning users and understand more deeply what the story is behind things, and then create your categories from there. If you create those predetermined buckets out of nowhere, you might be missing significant cuts that you want to be able to track over time.”

Interview churners BEFORE locking in your cancel-survey buckets

Don't ship a cancel survey with buckets pulled from a brainstorm. Run qualitative interviews with churners first, then turn what you actually hear into the predefined options — otherwise your segments will hide the very reasons you most need to act on. Re-open the text field periodically to catch new failure modes.