Who's making a business from social media? Audio and video producers are, for the most part, scraping by, give or take a few notables (several of whom are being paid from venture capital money). Bloggers are making money in varying degrees, depending on their advertising and/or consulting opportunities. I'm going to leave the entertainment category out of this discussion for that reason (though you're welcome to argue it back in). So, who's really making a business from social media?
First to market with actual paying jobs in social media are public relations and marketing firms. Why? Because if you squint your eyes, the tools are the same thing: a means for communicating professionally. Is that wrong? I don't think so, provided we don't lose ground with regard to how these new tools rehumanize technology-assisted communication.
Using social media for viral advertising is popular, but mostly because it's low-cost, low-barrier technology that permits folks to get a message across through different channels. Will that last? I can't see why we'd go back to $100,000 spots when we can create the media and distribute it for free, especially where the world is shifting to those free methods, too.
I'm not sure what department an internal corporate social media practitioner would fall into. Project management makes sense, because inside the firewall, these tools facilitate collaboration, ...