750 million people do not migrate immediately. I stand by my statement, at this point in time, Facebook is too big to fail.
Many people take issue with that by bringing up MySpace. MySpace never got this big, not even close. MySpace had no such thing as "MySpace connect." MySpace never had an entire application eco-system. Businesses never really adopted MySpace. To compare Facebook now to MySpace then is to fundamentally misuderstand the current social media landscape and how far it has developed. It took years for MySpace to finally die off entirely.
In the context of this article "My Painful Realization," saying that Facebook is "too big to fail" means that in the forseeable future, Google+ is not going to replace Facebook, it is simply added to our channels. Think about your own network and tell me that your mother and less tech savvy friends are jumping ship from Facebook where "all of my friends are" to go to a new network populated, currently, by techies, geeks and early adopter.
I know that the concept of "too big to fail" is political-charged given our subprime mortgage meltdown. In this particular case, I'm willing to stake my reputation on the theory that Facebook is too big to fail and here to stay, at least for the near future.
I personally love G+ and think it is 100 times better than Facebook, but that doesn't mean that the average user cares enough to leave Facebook.