In this spirited recap of the 1980s, marketing consultant McKenna elaborates on a revolution in the computer-age marketplace that has all but laid low corporations whose isolated managements used massive advertising campaigns to dictate what the customer would buy. Today, he writes, the focus is on direct consumer contact and personal relations with the business "infrastructure"--media, suppliers, analysts, etc.--whose feedback will influence product development and marketing strategy. McKenna traces the rise and occasional fall of many start-up companies in the turbulent, proliferating computer and software industry, including the competition between Apple Inc. and IBM, a battle recently ended when the two signed agreements to work together on research, development and marketing.