This one flew under my radar but apparently Sprint installed several hundred kiosks in movie theaters across the country, and Ive walked past mine for a few months without looking at what it was.

What you do is walk up to the kiosk and it will tell you to text a message to a number and in return it will send you a message back. You then hold your message on the phone up to the red sensor and the screen will let you pick out a discount. Ours let you select from $1 off popcorn, drinks or snacks though it may differ depending on your theater. Tuesdays are $1 drinks and popcorn night at ours so that means free popcorn for the movie.

It would be helpful to know what chain of movie theaters you found the Sprint kiosk at.