Sprint and Fandango have partnered together to lower the prices of movie tickets. Through August 14th, you can register your mobile number to help reduce the price of tickets. The more people that register, the lower the tickets cost (the lowest is $4 a ticket). Then on August 15th, you will be able to get your promotional code that is worth up to $14.50. You will have until October 15th to use your code. This is limited to the first 100,000 people who register.
I read through the terms and it doesn't look like you have to be a Sprint customer to participate.
(Thanks B'ham Bargain Mom!)