What are some alternatives?
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.
Sellfy - Sellfy is an easy to use but powerful e-commerce platform where you can sell digital, physical or subscription products. Use a Sellfy storefront to create a beautiful online store or embed a Sellfy shopping cart to your own website.
Payhip - Upload e-books and sell directly on Twitter, Facebook or your website! Sell your ebooks to your fans and followers and get paid instantly via PayPal.
WooCommerce - A freely available eCommerce plugin that enables shop facilities on your WordPress website. Functionality enabling extensions & beautiful themes available.
robora - Robora is a service which aims to help you sell anything, anyway you like.
Helium - Helium lets you accept payments by credit card for anything you want to sell online.