I imagine you'll see this a lot more post SMT's. Like this is already happening on the Steem Engine tribe sites. They have the option to add ads and the ad revenue is then used to burn tokens.

When you have Communities that have their own SMT's, they'll be able to create their own frontends and economies around their own token, similar to tribes. Then these frontends will be able to add ads, or a multitude of other monetization options and use the revenue to buy back the tokens.

In the future, I see Steem as being your first step, where you can grow and nurture your community for free, then once it gets big enough, you can branch off and create your own token and frontend and start to monetize.