The group discount service Groupon shoots your a smile on your way out the door. They introduce you to Derrick, the fictional employee who originally signed you up for the service. Then they let you punish him. I won't spoil it for you, click through for yourself to see it in action.
I don't know if it works or not, but if it was me I'd think twice before I actually decided to leave the service for good because of this.