This is all headed to one login for all your email, sms, chat, etc. Gmail, Hangouts, Voice are all converging. Communication is far more valuable from a data science (aka marketing) standpoint than "social." Who you have as a "connection" on any network is nearly meaningless now, however who you actually talk to is very valuable information. This is why (not trying to start a political discussion) NSA stores meta data about who people talk to on the phone.