NONFICTION : WHATEVER HAPPENED TO MADISON AVENUE? <i> by Martin Mayer (Little, Brown: $22.95; 304 pp.).</i>

What happened, according to Mayer--who first wrote about the business 30 years ago, in “Madison Avenue, U.S.A.”--is that it got big (multinational, in fact) and cautious (with a few grand exceptions), and technology made too many clients wonder if it was so important after all. This is a decade of transition for the industry: Network TV no longer has a stranglehold on the consumer, remote-control zapping has changed the way we watch all television, and specialty media abound, promising to reach the desired segment of a splintered audience. Much of what Mayer has to say about the changing times, and advertising’s response to them, is for industry ears, though readers curious about why they buy the toothpaste their mothers bought will find interesting material here about the birth, and building, of a brand. The best factoid is the table that lists leading brands in 18 categories, as of 1923, and then their current position. For all the marketing strategies and advertising, only two have slipped to second place; the rest retain their preeminence, testimony to the power of an established brand and the frustrating inability of subsequent advertising to break through to the top.