On Peter Kirns excellent "Createdigitalmusic" blog he interviews elecotronica artist Tricil regarding their experience using Topspin Media and comparing it to Bandcamp.
Bandcamp’s charm when they came out in the post myspace-era was an embeddable, music-centric streaming site that had built in social-sharing, almost like SoundCloud with a commerce function. With Bandcamp, you can set up “In Rainbows”-style pricing of pay what you want and even do a free in exchange for an email much like Topspin. The downsides to Bandcamp are a sandboxed site with little to no css customization, so it’s harder to create a more “branded” presence going the all Bandcamp route.