Most staving artists are already "selling out" -- the reality is that if your audience is small that selling t-shirts on cafepress may give you some coffee money if you are lucky but not enough to earn a living. In fact most artists already support themselves with other jobs to make their art, so there isn't much time after that left to promote it. And then lastly art is art -- even if it's great, it just might not be the right thing at the right time and the right place.