The thing I like about some of the new sites is the amazon style recommendations

"people who bought this also bought this"

Then the more you buy, the more you get matched. Like the tivo of mp3 music - after a while the site just recommends stuff you will like based on what you bought previously.

Unfortunately whilst this is great for the user its of little use to the promoter. I'd look at buying banner ads on the site to click through to your track - get them at the point of sale. If its good it will get bought.