And that's the promise of Mastodon. It is free because each instance pays the cost of keeping it alive in the form of hosting their instance. Like, right now, the NYTimes acts like a "database" with all the pages, and reddit or twitter like the content distribution feed, and both need funding. But if the NYTimes had its own Mastodon instance and published there, the rest of the Mastodon network would be its content distribution feed, each federation funding itself.
As a sidetone, it even solves the problem of verification I think, because if I have the Mastodon account [email protected] for example, I don't need a central system to confirm that I'm working for the nytimes, like for example twitter would.
And moreover, since Mastodon is just Atom, if people want to just see feed updates they can do that, or they can get a client that supports the full social features too. I think it's pretty cool.
I don't think social news delivery/publishing is an easily monetize-able business. Out of twitter/reddit, reddit seems to have found a model that works for them. Twitter hasn't found what works yet.