Lessons from dad-Thanksgiving coupons

Walgreens runs a Thanksgiving special every year where certain items give you a coupon for the same value you paid. These coupons are redeemable until December 8thish. The trick to keep getting

11 purchases give you 11 coupons. If you use a coupon for hair ties (but that is really good on anything in the store) on another product with the coupon generation special other than hair ties, you get a coupon for the new product. So you have two piles of things. You Seth coupons of one pile to buy the items that generate different coupons on the other pile.

The cycle ends when you purchase things that do generate coupons, like ice cream, or they run out stock on a few items.