Here's how it works: I upload images, and choose products which can be made from them: tote bags, keychains, refrigerator magnets, mousepads, and, funnily enough, coffee mugs, and a boatload of other stuff. Shoppers purchase items customized with an artist's imagery, but not actually made by an artist. The artist gets a royalty, which is not very damn much, but read the part about the images "just sitting on my hard drive" again. (I admit to feeling a tiny pinch of guilt over participating in the sales of mass-produced crap, of which there is already plenty in the world.
Here's the good part. If nothing sells, I am out absolutely nothing. I am still in possession of the images & the right to use them. All I've lost is a morning at the computer.
Wish me luck. This time I"ll kick that football from here to Australia!