Well, I work there, and I know that if you bring any empty ink cartridge *limit of 25 per day*, you'll get a $3 off coupon good for anything in the store. Most peeps just use it on the ink they're getting. The catch is that the coupons are only good for 90 days, and you can only use usually one per visit - so that means if you want to buy 5 items at the checkout, the coupon can only be applied for the total. Recently due to customer complaints though, we've had to resort to doing one coupon per transaction, so if someone has 5 items and say, 5 coupons, we have to ring them up seperately with each coupon. So you can still get away with it, but its time consuming. Hope that helps.