"The inescapable fact is that the universe is divided between Blondes and Brunettes. This is not a matter of the color of one's hair. This is a cosmic trait. The Cosmic Blonde floats through life on a beam of sunshine, from success to success. The Cosmic Brunette obsesses and reflects, frets and fumes, turns inward...writes and reads books, worries, condemns and evaluates, judges, discerns and doubts. The Cosmic Blonde water-skis."
Brooks admits there are "brunettes of the soul, and vice versa." Regardless of our hair color, we have to admit there are these two types of people in the world.
As marketers, we probably have both types in our target markets. Because there are so many kinds of people, we have to understand them if we are to sell to them.
There are, of course, "universal benefits" in many products. We all want to look attractive and smell good, for example. We all want to be healthy, and know what we need to achieve our goals.
For most products, though, we have to learn how to satisfy people's needs before we can interest them in our product. (For example, with perfume, we need to know if someone would buy it to smell good, to attract a lover, or to be like everybody else.) When we don't, we risk leaving out large numbers of people. Today we can't afford to leave them out by neglect. Even though their norms and desires may be completely different than your own.
For example, would the Cosmic Blonde want a Vespa for the same reason a Cosmic Brunette would? How do we know for sure? The Cosmic Brunette may worry about her Vespa being stolen while she's at work, while the Cosmic Blonde wants to make sure she is seen in it.
I don't feel comfortable with how Brooks categorizes people, but the biggest danger in advertising is to think everyone is exactly like you, and feels the way you do. They don't. We can't become myopic.
I'm a greying Cosmic Brunette, myself. I wonder what I mean by that?