MARKS OF EXCELLENCE, A FRESHLY REVISED BOOK FROM PHAIDON, COMPILES TODAY'S MOST IDENTIFIABLE LOGOS ACCORDING TO THEIR VISUAL TROPES. A brand is more than a logo. But a company's mark is its calling card, a shorthand for all that other stuff-the quality of the product, the level of service, the history of the company-for its composite brand. To understand the cultural power and currency of a popular logo, all you have to do is survey a set of preschoolers, who, while unable to order off a menu, can handily identify McDonald's golden arches, as well as the emblems of Disney and Nike, to name but a few. Once used as a means of denoting ownership or authorship ("This is my cow," or "I made this ceramic vase"), logos have evolved into creators of value, with consumers often willing to pay much more for products with identifiable marks than for those...