In practice, no one takes the time to gather that many facts. The amount of information needed to make a knowledgeable product purchase depends on such considerations as the cost of the product and the difficulty of obtaining further data. At some point, the cost of the additional information will exceed the value of the product. The average person is exposed to dozens of advertisements every day. A student may not appreciate just how influential advertising is until confronted with large numbers of familiar slogans, logos, and characters taken directly from the ads.
Teachers can encourage students to identify advertisements and examine their content.
Unscrupulous advertisers will sometimes advertise products that are just too good to be true. A child can learn that purchasers do not ordinarily get something for nothing. It is preferable if the child grasps this lesson before getting cheated, rather than afterwards. The more exposure a child has to the motivations that lie behind questionable advertising methods, the less likely it will be that the child will be fooled by such tactics. The relationship between advertising and consumer knowledge has been the subject of much study.