Inscribed on the walls of The Phelps Group is a maxim that reads, "Our work influences millions of people daily. Therefore, Truth is our highest value." Good words to live by -- and good words to sell by as well.
Why? Because no ad, no matter how clever or charming, can communicate and persuade if it's based on a false premise. I call it the "ring true" test. If there's something shaky about our assumptions, we not only lose our audience, we lose our credibility -- and our hopes of a sale. To win our targets' hearts, minds and business, we must first be believed.
In fact, a lot of ad pundits will argue that you make big points with your audience by being brutally honest. That is, if there's something unpleasant associated with your product, come out and say so. Remember the legendary Volkswagen "Lemon," and "Ugly is only skin deep," ads? This is the advertising version of self-deprecating humor. It's not only refreshing, it's endearing.
Bottom line: If you want to connect and persuade, find the central human truth about your product. When your audience sees you recognize that universal truth, they're much more likely to accept and believe your other assertions.