First, you would require to set up a business/selling account on whichever site you choose to sell your product. They will ask you to upload your product details for customers to view. Then, whenever a customer places an order for your product, you will be notified to ship it to the customer’s address; the partner site may also pick the package from you and deliver it to the customer, whichever way they work, or you opt to work. After all this, the partner site will deposit the payment in your account after deducting a pre-decided fee.