I have recently started my online print shop, it does Custom T-Shirts, Business Cards, Stickers/Decals and Rubber Stamps. Check it out! YunoPrint <– clicky!
Points system, whenever someone purchases a design you created, you will get 2 credits as a reward, this way you can print for free by just creating designs that people like. I am also planing to do a withdrawal system where you will be allowed to withdraw your points as cash if you have a certain amount of cash.
Again.. check it out –> http://yunoprint.com