ReDigi - ReDigi is the future of digital music.
Shoprocket - Add eCommerce to your existing website in 5 minutes.
Pixycart - Pixycart is another great way to sell your digital downloads: art, music, videos, photography...
Sellfy - Sellfy is an easy to use but powerful e-commerce platform where you can sell digital, print on demand or subscription products. Use a Sellfy storefront to create a beautiful online store or embed a Sellfy shopping cart to your own website.
Shopify - Shopify is a powerful ecommerce platform that includes everything you need to create an online store and sell online. Try it free for 14 days.
WooCommerce - A freely available eCommerce plugin that enables shop facilities on your WordPress website. Functionality enabling extensions & beautiful themes available.