Vacuum Salesman
A vacuum salesman goes door-to-door in a new neighborhood. When a woman answers the door at the first house, the salesman walks right in and drops cow patties on her floor.
He says, "Ma'am, just to show you how confident I am in the quality of my vacuums, I'll eat whatever the vacuum doesn't pick up."
The woman smiles and asks, "Could I get you some ketchup with that?"
The salesman scoffs confidently and says, "I assure you my vacuums have more power than any other on the market today!"
The woman replies, "Well, that may be so, but we just moved in and the electricity isn't turned on yet."