Gumroad is an e-commerce platform enabling creators to sell digital products, subscriptions, and physical goods directly to their audience with simple, automated workflows.

Smashwords is an ebook distribution platform and store for authors and publishers to sell and market their digital books globally.

Leanpub enables authors to write, publish, and sell ebooks and online courses with high royalties using a lean publishing model.

DPD is a digital product delivery and e-book publishing platform allowing authors and sellers to sell downloads with 100% of sales retained.