"Vaseline survey" joke
A market researcher was called at a house and his knock was answered by a young woman with three small children running around her. He asked her if she minded replying to his questions and when she agreed, he asked her if she knew his company, Cheeseborough-Ponds.
When she said no, he mentioned that among their many products was Vaseline and she certainly knew of that product. When asked if she used it, the answered was "Yes, we use it when we have sexual intercourse."
The interviewer was a little surprised. He said, "Everyone uses our product and they always say they use it for the child's bicycle chain, or the gate hinge or some other purpose; but I know that most people really use it for sexual intercourse, they just don't like to say so. Since you've been so frank, could you tell me how you use it?"
"We put it on the doorknob to keep the kids out!"
Not enough votes...