When you set up a home vacuum demo at someone else's address. They get a knock on the door and a persistent vacuum salesman cleans and shampoos their carpet. This demo usually takes several hours resulting in a pounding headache and angry neighbors. Bonus points if they cave and buy the vacuum!
My friend was telling me that his favorite hockey team was playing tonight. So I Kirby prank'd him. He missed the game and financed a vacuum. Sucker.