I just joined this in September, but I really wish I had done it sooner. It's a great way to earn money for kids' college without even trying. (Passively!)
If you're like me, you didn't realize that you can also stack manu and/or store Qs along with the Upromise Qs. With all the stacking I did last month, the manufacturers, Price Chooper, and Upromise PAID me to take their No Yolks Noodles, Nestle Choc, and Wacky Mac last month. (I also got a great deal on Cabot Cheddar and GOld Bond talc.)