Social Media didn’t start on “line” so to speak.
It started on telephones back in the 50’s. Once the internet jumped into the public grasps it spanned into IRC, Chatrooms and instant messenger + email and e-commerce for business and this is where social software was innovative and expanding faster than ever before.
Social Media then exploded back in early 2000 with social blogging, networking and news sharing with highlights such as Myspace, Bebo and Facebook.
In what form of social software you speak to someone using became a serious choice that you’d have to think about beforehand.