Shapeways is a 3D printing service, and most Poser/DAZ models are too complex to print there, but they also have a lot of options to make things from b&w or grayscale images, so you might find it interesting to check them out:
This guy : http://www.ianroz.com/page12.html - has a free ebook which lists several dozens of similar “sell your artwork” sites. The colour scheme of the book made my eyes hurt, and I wish there were reviews of those sites not just words taken from press releases, but still a nice list to have.