I guess the quote will explain everythig: “Today you dont need label support or a lot of your own money to make your music available for worldwide digital sale. Some labels may be a big help with marketing, booking and physical media distribution, but a few online services now enable you to easily upload your digital music to the major download stores and keep most of the money earned in sales. Read on to learn more about 3 excellent options including; TuneCore, WaTunes and Rebeat Digital.”
Useful article from DJ TechTools about selling your music online.
Article: Get Your Tracks Online