Smartest advertising thing you did?

Could you please share some stories on the thing you felt was your smartest investment/decision? What about stories that you have heard which you think the person in question was very clever.
I read about one guy whom convinced a small town to name themselves after the company name. I felt that was really, well, funny.

I used to sell fashion accessories and what I did is wearing them all so I look like a Christmas Tree in their eyes. But I got big sales.