Call me crazy, but I was raised with the idea that you should never buy an item (t-shirt, cap, whatever) with a logo on it, because then you would be paying to advertise someone else's product or service. With that in mind, I've tried to make my forum's CafePress offerings more than just a logo slapped on some generic merchandise. I've been sending out buttons with my logo for free, and give out logo t-shirts as contest prizes. Very, very occasionally will I see someone buy a logo item; the items utilizing other custom artwork from my forum sell much better. Do your members buy your logo merchandise, or wait for it to be given to them?