Which marketing adage states that a person needs to see or hear something at least seven times before he or she remembers it?

The Marketing Rule of 7 states that a prospect needs to "hear" the advertiser's message at least 7 times before they'll take action to buy that product or service. It's a marketing maxim developed by the movie industry in the 1930's. Studio bosses discovered that a certain amount of advertising and promotion was required to compel someone to see one of their movies.