Oh, that actually explains a lot. I used to offer a 7-day free trial for one of my apps that you could sign up for with an email, and the vast majority of the licenses were never used. The app wasn't even downloaded that many times.

I stopped offering the trial since I figured it was not useful for a relatively cheap (19 EUR) app that has a 30-day money-back guarantee anyway. (It can also be used for 15 mins without a license, but requires a restart after that.)