Do social networks influence purchases?

Havard Business School has an interesting study titled Do Friends Influence Purchases in a Social Network?. I would like to get my hands on the raw data (which is from the Korean social site Cyworld), but the outline conclusions seems plausible:

Interesting study and worth considering the implications for your social network analysis. As an aside, I was talking yesterday to a Marketing software company who were exactly focusing on that middle segment in their default parameters for their SNA module. Clever.