Yes. Exactly. The only reason I stay on FB is because my friends are there. If they all moved somewhere else I would probably migrate too.
What if they migrated nowhere? In other words, what if what has happened to, say, the New York Times happened to Facebook. That is, people didn't migrate into The Washington Post, they migrated into a distributed system beyond central control.
In other words, what are the chances that something like Disapora or some other distributed social network takes off? I'm perhaps polluted by having just finished reading Vernor Vinge's Randbows End, but it seems to like in the long term it's inevitable. The question is whether that term is 10 years, or 20 years.
I would say Facebook is practically untouchable in five years, possibly at risk in 10 years, and 20 years... well, the general public web isn't even that old yet, so I expect protocols and platforms I haven't even considered and the survival of FB will depend on whether or not they are a cog for those protocols, a spoke, or stuck out with a segment of the rim.
https://joindiaspora.com/http://en.wikipedia.org/wiki/Distributed_social_networkI don't know whether the final threat to FB will take that form, but it seems more likely at this point to seeing it destroyed by a mega-rival in the same way that the importance of Windows has declined not because someone else came up with the killer OS, but because thousands of people came up with tools and experiences that don't depend on a particular OS.
So, in that metaphor, I see Google here as building Mac OS X, while the real threat to Facebook is the web (if that makes any sense at all).