Whenever I tell anyone that I think Facebook is still undervalued, they look at me like I'm crazy. Of course, I deleted my Facebook years ago, suspiciously coinciding with about the time my mom got one... But trends, man. Facebook is still picking up users all across the world as more and more people acquire internetses. Edit: and retention is through the roof, probably 85% of everyone that ever used Facebook still uses it.
After all, more people use facebook than use the Internet.
Heh, didn't even have to click the link. Yeah, people are dumb. More proof that you should design your user experience and interface to accommodate the lowest common denominator.
There's nothing that says Facebook has to stick around. That's why I think it's overvalued... yeah, they've got ad revenue, but their ads poison their network. They know their shit is invasive and unloved so they have to ride the balance between "shit that makes us money" and "shit that drives our userbase away." That means they're one good competitor from death, and always have been. Fortunately for them, Gplus failed.