It depends on your audience. I agree with your point that they should reinvent themselves (I explicitly say those words in the article), but I don't agree that

It depends on your audience. I agree with your point that they should reinvent themselves (I explicitly say those words in the article), but I don't agree that any business with an audience has potential. Lets put it this way, actually using your example: If they do reinvent themselves as a student-only network, they effectively have no audience, because as you know, those folks are on Facebook. If they create a premium service and play the privacy angle, they'll be trashing 99% of their functionality today, and also alienating their audience. Things are definitely not that easy as "having audience" -> "being successful". Not in this case anyway.