I've been commissioning artists for a little over two years now, starting with site money on GaiaOnline and moving to dA from there. One thing that's hard for me to ignore is the number of artists who are concerned about being scammed, either because they've gone through that experience before or because the stories and warnings of it happening all the time proliferate. Commissioners have their own concerns about being scammed by artists. The simple fact of the matter is that it happens.
However, I think a good portion of the problem is that many people who want to commission an artist have no experience doing so, and it's not as easy to