If there are many people holding Dogecoins, and a percentage of those are pet owners for example, and I were a pet shop chain, I could simply create a promotion saying that you could get a discount by visiting their pet store and using Dogecoins as coupons. The store chain gets what it needs (ie: more customers spending money), and the customers holding Doegecoins get to use them to buy stuff for their pets. The store chain can then use the Dogecoin as rewards for returning customers and the cycle continues.

IMHO, crypto coins are the rewards coin of the future. There will be thousands of them, just as there are thousands of different rewards, airmiles, coupons etc. I would like that TAG become the defacto rewards coin of the future but I am a realist..