What you really need to be doing is educating the artists and those who come to see the work about the various Creative Commons licenses that are available. There is more than one form of license available.

Encouraging an artist to use one of the "non-commercial" licenses means that they will not be able to sell the work for commercial purposes, which is quite short-sighted. And you should be encouraging people to get permission from artists REGARDLESS of how it is being used, commercial or not.

Goddess knows, I give away a lot of my music, but I also get paid for a lot of it, too. Using the Creative Commons license doesn't mean giving up getting paid for your work, but it does mean taking responsibility to educate those who love your work.