As each wave of people mature into your target market... you have a steady stream of people who like your stuff. Even if it is plastic crap from china or digital crap from silicon valley.

This alone will be what keeps facebook afloat - the kids, and the desire of their familial connections to attempt to keep tabs of their lives.

Is it insanely profitable? No, we've realized that in the last few months - is it sustainable, yes. But even moreso, its cancerous to freedom...

Anyway - apps and services like this will be a never ending wave.