Genuine question... how is whatsapp a social website vs just a chat application? Perhaps I've missed something critical about it but the way I've used it and seen anyone else use it is just as a replacement for SMS
As someone who doesn't use WhatsApp in a country where everybody does: the primary use case appears to be group chat. If it was just a replacement for SMS, not having it would not be a problem - I could still text with people. However, I'm "missing out" on things because I can't be in some WhatsApp chat groups.
Any proprietary communications platform meant primarily for communicating between humans can be referred to as a social network. It's a pretty broad definition in my mind.
