In addition to Xena's comment, if the commerical license is for a movie or similar project, you may want to consider taking residuals as all or part compensation. This would typically be a % of the profits, the % depending on how important a part of the project the work is. A second point, there are levels of commerical use, so that you can give rights to use your work in a movie, for instance, but retain differet rights for spin-offs, sequels, etc., or retain residuals on all future use of the work by the production. I'd suggest asking for a more detailed explanation of the project (offer to sign an NDA) and if it sounds like a big budget project, get a lawyer with entertainment experience to help write the contract. If its a small project (or an abitious one with a small budget--like most of mine are;-), charging a small fee and taking a residual on the profits may be a good idea. Good Luck!