3D Hubs - Airbnb for 3D printing
Kwambio - Unique products made (3D printed) by you
Zazzy - Design and sell your own 3D printed jewelry
Growmax.io - A smarter, simpler B2B eCommerce Platform for manufacturers, wholesalers.
ZEUS - Scan, copy, print, and fax objects for 3D printing
Shapeways - Shapeways - 3D Printing Service and Marketplace