If you have a passion for music and a website, you can earn extra money selling music online without any upfront costs. Commissions aren't huge -- usually less than a dime for the typical sale of a 99-cent song. However, how well you do is primarily up to you. Back in 1970, a teenager with a love for music created the old-economy equivalent of an online music store, selling vinyl records through the mail. That teenager, Richard Branson, eventually turned his Virgin Records start-up into a multi-billion dollar empire.

Starting Your Website

To start an online music store you first need a website. Ideally, this should be a domain that you own so you can have complete control over the content and style. A domain name and web hosting fees can run about $100 per year. If you want to wait until you start earning some money before making this investment, you can use any blogging platform that gives you the ability to post ads for affiliate sales, or a shopping cart system for mail order items you might want to sell.

Digital Music Affiliate Programs

Every year more than 1 billion tracks are purchased in digital format and downloaded over the Internet. The two largest online retailers, Apple and Amazon, account for about 85 percent of this market. Both offer affiliate programs open to just about anyone with a website who wants to start selling music online. Amazon and other retailers, such as CD Universe, give you the opportunity to make commissions on CDs and DVDs as well. Once you apply for and are approved as an affiliate, you are given a referral code to attach to links. Post these links on your website. Each time someone clicks on a link from your website and purchases from the retailer, you earn up to a 5-percent commission on the sale.

Standing Out From the Crowd

It's relatively easy for anyone with a website to become an affiliate music seller and even easier for customers to bypass affiliates by going directly to iTunes or Amazon to download music. Creating a website that attracts customers is vital to online success. Instead of simply posting links to the most popular tracks, consider writing reviews of your favorite albums and searching out music that not everyone has listened to. You can also link to YouTube or Vimeo music videos, blog about entertainment news, or supplement your music sales with unique fan items such as T-shirts and posters.

Selling Your Own Music

If you're a music lover who wants to take a hands-on approach to an online music store, you may prefer selling CDs, vinyl LPs or even musical instruments. To do this, set up an account with a service like PayPal.com, which lets you set up a shopping cart system and accepts credit cards without any upfront fees. Alternatively, you can create an account on online marketplaces like eBay or Shopify.com, which give you everything you need to create an online store on their websites. Shipping is something you will need to manage yourself, so research the cost of shipping the items you want to sell before setting a price.