I don't think that is really a meaningful comparison. Consider that Gmail's inbox is a effectively a stream of posts. It has contact management, IM, and several

I don't think that is really a meaningful comparison. Consider that Gmail's inbox is a effectively a stream of posts. It has contact management, IM, and several different notifications (on the phone, count next to inbox and in title, you can enable popup notifications on your desktop). No one says that Gmail is modeled after facebook.