It seems that when MySpace Music bought Imeem, it didn't acquire its outstanding debt, which included payments to indie artists for music sold.
Read the Wired blog article MySpace/Imeem Deal Leaves Thousands of Artists Unpaid
This is another reason why it pays to lead fans to your website to buy your music. ;)
Small but important update: You can now give a free track or album as an incentive for fans to sign
up to your mailing list. Offering an incentive like this is a great way to get casual visitors to subscribe.
You'll find this option in the "members options" section of the Mailing List tab.