I think I'd actually use an auto vote service if it was simply an option that comes standard on something like Peakd. If I was designing the feature, it would simply be a button on the profile, like the follow button, but it would be called 'Subscribe', from there tweak a few parameters and done. Now I am a 'Paying Subscriber' and when I login, notifications alert me of new content I've subscribed to, and I'd even go so far has having a feed that only shows content I've subscribed to.