It appears the few folks who have tried mobile coupons have shown lots of promise.

Planet Funk, a fashion retailer with stores in California, Texas and Colorado, sent out a series of mobile coupons to users before their Black Friday specials last year. Of the 2,000 participants who signed up for the coupons, the retailer saw a 91 percent redemption rate. Ninety-one percent! Now that's staggering.

What's even more impressive, is the "rate of investment" (ROI) was well over 300 percent. In marketing talk, that simply means that the cost of turning out mobile coupons compared to the new traffic it brought in was... well, astounding. Normally, companies that produce traditional coupons incur costs on the production of the coupons as well as the loss of profit margin on the savings when people use the coupons. The idea is that you make that up in volume.

You can read the gritty jargon-filled details here: 

http://www.mobilemarketingwatch.com/fashion-retailer-sees-377-roi-using-mobile-coupons/