I've been using the 15% off coupon that's floating around on here...i've used them at least 10 times already. I brought them with me to use for my furniture this weekend and the computer wouldn't take them. They said it must have finally recognized that the barcode has been used previously. She mentioned something about the computer they are printing from. I'm going to try to print from a different computer if I need to use them again. Just wanted to give a heads up if you've been using them you might have a problem.