Its certainly true. Another thing - people can get REALLY crazy about contests due to not wanting to lose out. Here is a true story:

A supermarket chain I worked with ran a weekly drawing. You had to register one time and your name was put in a big drum. Then you were given a card that you had to have punched each week. If your name was pulled, you had to show your punched card. If no winner, the pool built by $500 each week.

Once a prize got above $10,000, folks really got excited and our sales jumped. Some people got so involved with it that they wanted us to take their name out of the drum if they were on vacation for that week - they did not want to be announced as a winner and then not get the money! Of course this was just not possible. These folks were truely upset that we could not do this.

Funny how we react.