[Quoth]

Is there proof Prime is the bulk of customers? Though certainly most customers are regular, not "drive by" once off. Also the subscription model overcharges the occasional users and subsidises heavy users of a service. Of course Amazon wants more Prime subscribers, it's extra profit. Greed. That's why even today with the flexibility of how encryption works compared to analogue era, that almost no-one in Pay TV or streaming offers a la carte. There is a basic large package and then things like sport are an extra level. Only special events generally are pay per view. I'm not sure if broadcast pay TV still does PPV movies, I'd imagine streaming is killing that.

Most people would be better off and have more time for what they really want if they cancelled all subscriptions and purchased the content they want.

Subscriptions are parasitical and more profitable because the consumer is paying more and content creator is often getting paid less.