CD Baby just lowered its commission on MP3 sales from 25% to 9%, making it the lowest of any of the digital retailers, including Bandcamp, which powers the store on this site. And the new rate also applies to sales that come through any of their direct-to-fan sales modules, like the MusicStore for Facebook. CD Baby has probably the most complete set of artist tools of any of the independent music distribution services, and they just keep getting better and better, even since founder Derek Sivers left in 2008. It’s hard not to like this company…