I thought I would mention a company I just came across, SavingStar.  It is similiar to Cellfire.  They offer e-coupons that can be added directly to your store rewards card, but with one big difference.  Rather than the coupon amount coming right off of your receipt, instead it is credited to your SavingStar account.  Once you have redeemed $5 worth of coupons you can cash out for Amazon gift cards or have the money sent to your Paypal account.  What I really like about SavingStar is that you can add your drugstore loyalty cards as well.  The coupons are loaded to your account so no matter what store you end up buying the product from, you will get credit.  To get started click Here.  Let me know what you think!