I think it's pretty much inevitable. As Facebook is getting larger and larger, it gets harder and harder for them to grow users/revenue/time on site. So they s

I think it's pretty much inevitable. As Facebook is getting larger and larger, it gets harder and harder for them to grow users/revenue/time on site. So they start adjusting some things so they keep growing. But these things also make Facebook less compelling for existing users, which leads to eventual attrition.