I think you are missing the important part of this idea, probably because Seth wrote way too many words for something that could be compressed into a paragraph

I think you are missing the important part of this idea, probably because Seth wrote way too many words for something that could be compressed into a paragraph with an hour or two of careful editing. Of course you can get the idea that people who like one thing also like another from Amazon -- but Seth's senario presumed you knew that already. The problem is, figuring out WHO those people are that like both bands, particularly, the people who like both bands but don't know about your band to like it yet. The fact that there is an intersection of sets is easy to come across or guess, the actual MEMBERS of the sets are hard to find. Seth's idea seems like a good one to me because it fits the general pattern, that many good computer revolution ideas allow small people to do what huge companies, institutions, or governments were already doing. Putting the "desktop" in desktop publishing, personal computers with spreadsheets replacing custom code on mainframes, ebay replacing the Sears catalog, etc. Previously, the information of who these people were who bought CDs of band A and might like band B was available only to the big distributors. But since ebay, half.com, and amazon's used section allow us small guys to be distributors also, now we on a small scale can get access to that information too. I don't have any product that I can use to make use of this idea now, but I'm going to keep it in my bag of tricks.