The short answer: CD Baby.
“We’re excited to let you know that starting today, you’ll be making more money from your MP3 sales at CDBaby.com. We’ve simplified our digital-download pay structure, and we did it to benefit you. On every digital purchase (single song or album) made from CDBaby.com, you’ll get paid 75% of the selling price. That means for a single-song download priced at $0.99, CD Baby has lowered our cut, so you’ll now make a little more than $0.74 per song. That’s more than any other major retail site! And don’t forget: you can set the price to be whatever you want.”
Read more HERE.