a good understanding of human weakness is essential if a company wants to sell a product. One way that advertisers persuade us to buy a product is by targeting our dissatisfaction with ourselves, our fears. Consider for a moment a typical fear-fear of being offensive to other people. Advertisers persuade us, for example, that if we don't buy their mouthwash, we'll have bad breath and offend other people. Dentists tell us that mouthwash is actually unnecessary; they explain that we need only simple dental hygiene-regular, correct use of a soft toothbrush and of dental floss. But we continue to spend money on mouthwash, breath freshener, and breath mints. Our fear of offending people outweighs our dentists'logic.