A more common variation of this idea is "Win your purchase free!", with the odds of winning being fairly low, but the price remaining the same. Car dealerships

A more common variation of this idea is "Win your purchase free!", with the odds of winning being fairly low, but the price remaining the same. Car dealerships seem to like this one, and Visa ran a similar contest here in Canada recently (called "Win What You Buy"). The success of this kind of promotion is most likely proportional to the price of your product.