I signed up for America's Test Kitchen one time, because they had a nice program for learning the basics. Probably used it for a couple months, and then I was done with that content and wanted to cancel. Of course, even though you can sign up online, you have to cancel on the phone. On hold for 20-30 minutes during work hours, then talk to the rep, then listen to their retention offer, then it's successfully cancelled.
I actually loved the content, and would probably have resubscribed for a month here and there. (Cook's Illustrated is part of the same group and their content is also great.) But I will never do it again because of this experience.
How many people decided to get the new Playstation next time because of a frustrating experience cancelling their xbox subscription? You won't see those numbers in a spreadsheet.