I can see the problem with the current reward model being that you get paid one off on steem while if you hosted a blog and signed up to an ad network you get the evergreen effect.
I can think of two possibilities for steem. the first one (inspired by the solar hint) some sort of contribution of resources to help with scalability issues.
the second some sort of reward per view system like the BAT/brave project.
RE: How many of you would like to see evergreen content on steemit?