I just finished up reading Search Marketing Standard magazine (a great read by the way and I would recommend it to all my friends and colleagues); specifically a few articles/interviews about social media marketing. In an awesome interview with Cameron Olthuis about the State of Social Media Marketing, he talks about achieving front page placement on Digg and it’s affect on inbound links. He also talked about control (or lack thereof) when marketers engage with social media; as well as measuring social media. He made some really great points.
The other article I read was written by Chris Boggs called Is Social Media Marketing Finally Coming of Age? It was a great read as well. The topic of Digg and links also came up; and he also touched a little on social communities, bookmarking, etc.