What's Your Biggest Marketing Flop?

I usually ask my audience this question whenever I do a training seminar or speaking engagement: "What is your biggest marketing flop?"

Here's a snapshot of responses from a recent group--

I placed a single ad in the newspaper to promote an event. Received zero response.

Have not had any success from newspaper advertising.

We planned a private retail shopping party. From the RSVPs we thought we had 25 people coming and planned food, staff, etc., accordingly. Only two disinterested people showed up, and we did not sell one dollar's worth of merchandise.

When I was starting out in business, I got my first call from a reporter. I did not prepare, and the call caught me off guard. Needless to say, my message did not come across in the story as well as it should have.

I have not had any response to my "yellow page" ads.

Have you had any experiences like these? What could these folks have done differently? Let's hear from you marketing geniuses.