According to a recent independent report by market research firm NPD, digital music sales currently account for 35% of all music sold in the US. What’s more, those numbers are expected to go up, equaling CD sales by the end of 2010. As far as music retailers go, iTunes leads the race, accounting for 25% of all music sold as well as 69% of digital music sales. Trailing behind iTunes, Walmart and Best Buy fall into second and third place for leading music retailers, and Amazon MP3 takes second place for strictly digital sales.

Enough of the numbers”the bottom line is that now more than ever it’s important to make sure your music is able to be purchased online. And there are hundreds of online stores where you can stock your music, from iTunes to Napster, Lala, Amie Street, Rhapsody, eMusic and more.

The question is, how to go about it?

Well, there are lots of avenues to explore. Some online retailers require you go through a digital distributor (iTunes), while others will give you an option to self-publish and distribute your own material (such as Amazon MP3). Typically, the easiest way to get on the retail sites you want, is to go through a distributor. The four main players in this arena are Nimbit, Snocap, CDBaby and Tunecore.

The good news is, there’s no exclusivity agreement with any of these companies”meaning if you’re willing to shell out any applicable registration or set up fees then you can sign up with all of them. But make sure you know exactly which services you’re getting with each one. Here are some questions you’ll want answered:

¢    Can you sell CDs, MP3s or both?

¢    Can you sell MP3 singles, or just albums?

¢    What is the commission deducted for each sale?

¢    Which retail stores does the distributor have a partnership with?

¢    Can you sell direct-to-buyer (via widgets for social networking sites)?

¢    Are there annual fees or payouts?

¢    Can you collect email addresses or other information on each seller?

Once you’ve done your research, you should be able to decide which distributor(s) to go with. And with their help, you may finally start hearing the sweet sound of cha-ching, bling-bling or maybe even ring ring ”you know, when your friends and family start calling and asking you for money.