These guys offer 50% commission which is fantastic, I usually get between $10 and $30 per referral / sale, depending on which package bands sign up for. I have made $3000+ USD so far.
As a musician my self I found their service to be fantastic place to easily distribute my music to all the major music sites so I have found this affiliate program easy to sell as product is as stated & is a wanted / needed service for many professional independent Musicians & Bands out there.