I'm sure many use my work as wallpapers. That's one of the reasons why I offer up fairly high quality images on most occasions. When it comes to selling them, I'm content earning what I earn here. I do hold on to the files I use for production, and can offer a much higher quality version for printing purposes. Those I sell, but not many are interested in purchasing. As long as things are going well here, and enough people recognize the quality and vote, I'm happy enough.