Google Maps with coupons

Well, now that business can offer coupons to customers via Google Maps, I am just wondering whether this is all that is needed. I get the impression that coupons are rather old-fashioned (although I admit that Americans are more crazy about them than Germans tend to be). So, while I like the idea of being able to use coupons, that should be completed by some bonus system, e. g. when I enter a store that I found via Google Maps, I can collect extra bonus points when doing a purchase (could be as easy as sending an SMS to the customer as well as the store in question and then check the customer's bonus card at the cashier's desk). I'm just wondering how tedious it will be for businesses to create their own coupons or to integrate their couponing mechanisms with Google Maps. And perhaps there's a few other issues I haven't had the time to consider ...