However, the barrier to entry against what they provide is pretty low. Yes, they have this fantastic database - but many people are wary of FB's data collection

However, the barrier to entry against what they provide is pretty low. Yes, they have this fantastic database - but many people are wary of FB's data collection activities and are guarded with what information they share. My point being, there is low probability they are the last, final large popular social network. The effort necessary to visit, use and become active at other web destinations is simply too low. I personally believe we'll see a flowering of special interest social networks - like github & HN is for us, but across the spectrum of human interests. Such targetted-interest destinations provide a social service FB or G+ is not going to provide. And they don't need to. These other social networks are probably already out there, growing their sub-culture communities right now. Look at Pinterest for example; they appeal to a specific subculture and have decent traction at the moment. FB is like pop radio - too generically bland. Specific purpose social networks will eventually dominate, I believe, because only in such an environment is sophisticated dialogues about the subculture subject matter at hand possible. At the more generic social networks ones' deeper, technical exchanges get interrupted by "friends" interjecting meme humor or other info-noise to such exchanges. Who needs that when trying to be serious?