> I imagine if you open the Spotify app and it said that it's a subscription service and you must have a Spotify account to login and listen to music, and nothing else, the vast majority of people would figure out to check their website to sign up.
I'm not so optimistic. I'd presume a nontrivial number of people would be confused and leave a 1-star review. I can't imagine how many people are confused about how the Kindle iOS experience works.