Good perspectives as always, thanks! Agreed that the person-to-person social networking aspects have been steadily de-emphasized over time in favor of a more media-focused (and ad-friendly!) approach -- although they're still there.
The framing I remember from the time was that social media was the general category, including social network sites as well as other options. Classic blogs, message forums, media sites with comments, chat rooms -- places where you can't follow other people -- are all examples of social media that isn't a social network site. Of course the people using those technologies are part of social networks, and so are people who aren't even online, so "sites" is load-bearing in that definition! Edelman's The Social Pulpit, from 2009, is an interesting look at how the Obama campaign used social media in general, and social network sites in particular (although leaves out the "sites", sigh).
