Many, many (many), years ago I put a flyer up on an outdoor bulletin board that said:

SEX SEX SEX (In big letters)

Now that I have your attention, this has nothing to do with sex, I’m looking for a roommate…

There was a bench right next to the board, so I sat for a while and listened to people react. It worked, in that several people stopped, laughed, and commented. But, in hindsight, I wasn’t surprised that no one called.