Gumroad

Gumroad is a platform where you can sell virtually anything digital: e-books, templates, presets, music, courses, software, and memberships. It's run by the company of the same name, founded by Sahil Lavingia, and over the years it has become a classic among independent creators. It's ideal for indie creators who want to start selling right away, without a developer and without building their own online store.

The principle is as simple as possible: you upload a file or set up a product, set a price (even 'pay what you want'), and get a link you can share anywhere, or keep your whole profile page on Gumroad. The customer pays by card, you get the money, and Gumroad takes a percentage of each sale. No monthly flat fee, no fixed costs up front.