What I'm curious about, though, is a far more general question that this brings to mind. How do you build a social network that sustains itself through community rather than advertising dollars? Is that even possible?
You could decentralize it and use end users bandwidth and storage to make it cheap to operate.
The crucial problem is the onboarding of users. Once you reach critical mass everything else is easy.
Reddit seems to spend more than it brings in in a year, if reports that it had $20 million in cash when Conde Nast spun them off and had $18 million in 2013 are true.(1) Reddit also has ads. It doesn't seem like Reddit gold is sufficient to keep a large site afloat.
(1) http://allthingsd.com/20130109/reddits-funding-round-is-for-...