Diet Coke two-liters are on sale with a buy more, save more promotion at Target. Pick up five bottles for $5.00, or pay $1.25. Buy one and use a $1.00/1 Target mobile coupon. To receive the coupon, text DIETCOKE to 827438. After the coupon, pay $0.25! Keep in mind, this is the same Diet Coke mobile coupon that has been available since 5/1. If you have already redeemed it, you cannot redeem it again.