There are numerous options for Print On demand business. For example, you can sign up with Amazon merch, redbubble or zazzle, and upload your design, customize on the products you want to sell and list the product for sell. You can also integrate print provider like printify and printful with ecommerce markets like ebay and etsy and start selling products through these markets. Or you can create your own website and integrate print provider and start your print on demand business. Apart from the familiar names like Redbubble, Zzzle, Amazon merch, Printful, and Printify, there are a lot of other platforms in the print-on-demand business model.