Off the top of my head I'm thinking there could be a front-end where content creators can choose a subscription level, for example 100 SP, to have access to their content. So that means if I want access to that content I have to have at least 100 SP in my account and then when i click some button to access a particular piece of content it will "unlock" it by submitting an upvote from my account.
Patreon 2.0?
RE: HF21: What Makes Steem Valuable?