Ever wonder why I am able to get so much stuff from CVS for dirt cheap? I always have anywhere from $5-$10 in ECB's (their store reward coupons) that I use to purchase products that yield me more ECB's. Walgreens has a similar thing (called "Register Rewards), except Walgreen's registers suck and usually beep and the cashiers don't know how to override them to get legitamate coupons to work. Anyways.
Another great example of this is Target. They frequently have deals where you buy a certain item (or number of items), and you receive a $5 Target gift card in return. The beauty of all of these transactions is that you can use manufacturer coupons on the items as well. Remember when I got A TON of frozen food for super cheap at Target last month? Well, every transaction I did, I would use two $5 Gift cards to pay for my purchase, and each transaction would yield me two more $5 gift cards (when I purchased the required number of items).
So far with my $10 in Target gift cards, I have "rolled" them twice, meaning I took advantage of two other deals which produced $10 in gift cards, while allowing me to use coupons and pay with my gift cards. I bought 10 Glade candles for $8 out of pocket (making them $0.80 each) and I received $10 in gift cards back. More recently I bought 2 bottles of Olay lotion and 2 bottles of Olay face wash for $1.40 OOP!!! And then I received $10 in Target gift cards!! Crazy! I used the gift cards in another transaction to buy 2 bottles of Olay moisturizer...and didn't get quite as awesome of a deal (the moisturizer was more expensive than the other items, but I needed it and after coupons and gift cards it was still more than 50% off!)
So for everything above I spent $8.78 (plus tax) and saved $26 and received $10 in Target gift cards!