18 months after I created it, I have sold it again. The first time I used this was as a custom 404 error page. I have sold it again as a character for a splash page. The background is a transparent PNG so the shadow blends in with the CSS background. Selling usage rights just makes sense, and yet so many illustrators are hesitant to do it. Copyrights turn fun, but unprofitable jobs into residual income streams. Be sure to be specific in your contracts; time periods, usage, how where and when. Clients generally are all for paying less for limited usage rights. In the long run, unless it is VERY product specific, an illustration can be used multiple times in limited ways, providing income again and again.