I never liked 7-eleven's buy 2 get 1 free deals...
You go in wanting just one soda. But then that lure to save a buck entices you.
Your mind says buy 1, but your wallet says buy 3 and save the rest for later.
Your mind replies, "But then they'll be warm," and your wallet says "look buddy, how long do you think i can hold on to the pennies you have now? Don't go crying to me when your broke and thirsty!!"
Your mind say's, "OK OK!! I'll get 3," and your wallet says, "Good... and buy some gum while your at it... MMMM gum..."