I’m always on the lookout for photographers who use social media to build an audience and then leverage that audience to success by selling them something or attracting commercial and editorial clients who are interested in the audience. There are lots of examples where photographers attract other photographers by talking about the business or their process for making pictures, but the real potential lies in attracting consumers outside this industry.
I’ve been lecturing about social media marketing for artists for several years and my go to examples of this are: The Sartorialist, The Cobra Snake and The Selby, all three of whom built their careers (in varying degrees) using social media. A few years back I was happy to add to this list an established photographer (Michael Edwards) who took a tried and true formula (nearly naked wormen plus tumblr), but added in his skills as a pro picture maker, and watched the whole thing go viral: http://meinmyplace.com. But, the success in the whole endeavor lies not in his ability to attract hundreds of thousands or horny college kids to his site, but to leverage the whole thing into a monthly column at Esquire, which he did for a year and a half and has since moved it to Playboy.
PDN has an interview with Michael (here) where you can get the full story.
If you want to study success in social media with photography these 4 are excellent case studies and pioneers in the industry.