Bar code coupons on smart phones

Along with many other retailers, Macy's has made it easier for you to get savings. You text the key word to a number and receive a message back. The message includes coupons on your mobile phone so you don't have to hassle with printing and carrying them to the store. Just show the barcode on your phone at the register to be scanned. I think this is a huge convenance that could build spending by having the coupon on your phone (which we always have with us) and not having to remember or dig out a coupon.
Macy's is very big on sending coupons to their credit card holders, this way you don't have to have a Macy's card, but still get the discount.