One nice niche market is The Horror Mall. They know their product and sell limited editions not available anywhere else. Their affiliate structure allows everyone to play and lets the customers decide what is good, not some cabal of secret gatekeepers.
Check them out (I'm sure most of you have).
I love the movie, Hype!, and I think it is appropriate to point out the pitfalls of manufacturing cool. (The movie is fantastic--a documentary about the rise of grunge in Seattle during the early '90s. We all know how that turned out.) If you haven't heard of/seen the movie Hype! I leave you with this: