A 3D printing marketplace is a website where users buy, sell and freely share digital 3D printable files for use on 3D printers. 3D printing marketplaces have gained popularity along with consumer 3D printers.

3D printing marketplaces are a combination of file sharing websites, with or without a built in e-commerce capability. Designers upload suitable files for 3D printing whilst other users buy or freely download the uploaded files for printing. The marketplaces facilitate the account management, infrastructure, server resources and guarantees safe settlement of payments (e-commerce).

Some of the marketplaces also offer additional services such as 3D printing on demand, location of commercial 3D print shops, associated software for model rendering and dynamic viewing of items using packages such as Sketchfab. 

Here are some well known 3D Printing Service Providers:

https://www.stratasysdirect.com