CardCash is running a 4% off coupon code on their site (code BLACKFRIDAY). You can use that on top of the deals that they already have. For example, iTunes cards start at 11.45% off. That makes the total savings 15%.

They have a huge selection of cards, but remember that these are resales so you will want to use them in the first 45 days during your guarantee period.

http://www.sunshinerewards.com/shopping/CardCash/