The advertising industry prides itself on being brand builders. Building successful brands is supposed to be the essence of what we do. But in recent years the ad industry has been guilty of cheapening some of the most important brands it controls -- its own. I am going to be picking on WPP because it is the biggest offender. But to some degree the same can probably be said about each of the major holding companies. WPP is the owner of some of the most famous and worthy brands in the history of the ad business: JWT, Ogilvy, Y&R and Grey. It has been systematically dismantling the value in these brands. Today they are splinters of what they were. The holding companies have undermined their agencies from the top down and from the bottom up. What a holding company usually does is buy successful brands and manage them at arms length to, presumably, add value to shareholders. Examples of successful holding companies are Berkshire Hathaway and Procter & Gamble. Nobody buys a Berkshir...