Gumroad - An all-in-one solution to sell your work and grow your audience.
Payhip - Sell digital downloads, courses, coaching, and more from one simple platform.
Easy Digital Downloads - Easy Digital Downloads is a complete eCommerce solution for WordPress.
robora - Robora is a service which aims to help you sell anything, anyway you like.
Ko-fi - Ko-fi offers a friendly way for content creators to get paid for their work.
WooCommerce - A freely available eCommerce plugin that enables shop facilities on your WordPress website. Functionality enabling extensions & beautiful themes available.