What do consumers really want? In the mid-twentieth century, many marketing executives sought to answer this question by looking to the theories of Sigmund Freud and his followers. By the 1950s, Freudian psychology had become the adman's most powerful new tool, promising to plumb the depths of shoppers' subconscious minds to access the irrational desires beneath their buying decisions. That the unconscious was the key to consumer behavior was a...