Hours of fun for business-epic junkies of all ages. Miller, a writer at the Providence Journal-Bulletin (Coming of Age, 1995, etc.), has wisely chosen his subject: an industry dependent on quirky creativity as well as extensive market research and hype, but ultimately at the mercy of youngsters' whims. It's a case study in market domination by megaconglomerates, which in this case are given virtually free rein over young consciousnesses, reporting only to shareholders. Miller's five years of access to toy giant Hasbro pay off in a visibly well-informed narrative of that company's vicissitudes and its rivalry with Mattel. Although he does justice to the range of toy genres, Miller effectively uses the many lives of G.I. Joe to dramatize the history of Hasbro and the way it works. Most readers will sense early on what it takes Hasbro years and millions of dollars of research and failed promotion to discover- -that Joe's days were over because ``the flag had lost its power over kids.'' But what we witness is the stubborn devotion to a brand over the creation of new ideas, as Joe becomes a blank slate for every ham-fisted attempt to keep up with the likes of the Mighty Morphin Power Rangers, culminating in G.I. Joe Extreme. But Miller's presentation is flawed on a superficial but irritating level. Instead of letting the participants emerge for themselves through their words and actions, the novelist in Miller rigs characters out of them from the get-go, into which their words and actions are often tediously jammed. It's worst in the soft-focus tribute to Hasbro chairman Alan Hassenfeld. Miller only does him a disservice with a starry-eyed portrait that could have been written by Hassenfeld's own PR department. Still, it's worth brushing aside the formulaic dressing for the solid, detailed cross-section of the mass-culture machine that lies just beneath. (Author tour)