Hundreds of well-known online stores like Barnes and Noble, Staples, and Overstock.com have a place within their shopping cart for a "coupon code" that gives a percent or dollar amount off your purchase. If you don't know the code, you can't take advantage of the discount. You can find these secret discount codes and coupon codes listed on many sites across the internet but the problem with these sites is that they're usually personal homepages and they don't maintain their lists! Currentcodes.com has a full list of available coupon codes