Uploading photos of my paintings to istockphoto.com may turn out to be a better idea than i expected. I only have a couple in istock's Vetta collection, but they're earning a nice little income.
I've probably earned more from them on istock than if i'd sold the originals. Especially the little 5x7 inch painting. That wouldn't have earned >$50 by selling the original. And i haven't incurred any shipping charge.
By taking photos of a painting's progress, i can also avoid the issue of ruining a painting by continually trying to improve it. Jackie always says, "leave it alone!" But i'm not completely satisfied, and it turns out worse than it was. By capturing it along the way, some pre-finished version might be quite sellable on istockphoto.
I suppose people are buying from istock so they can print and hang for their interior design.