The process turns conventional product development on its head. Over the years, multinationals have prospered by turning out premium-priced products for the world's affluent. Rather than also designing products for poorer people elsewhere, many businesses found they could simply pass yesteryear's models down, as if they were unloading fleets of used cars. Lately, big companies such as Microsoft (MSFT), Nokia (NOK), and Procter & Gamble (PG) are discovering that they can profit by targeting the world's masses first. And they can score again by selling these low-priced products elsewhere "The dominant logic holds that innovation comes from the U.S., goes to Europe and Japan, then gravitates to poor countries," says C.K. Prahalad, a strategy professor at the University of Michigan's Ross School of Business and author of The Fortune at the Bottom of the Pyramid: Eradicating Poverty Through Profits. "But now we're starting to see a reversal of that flow."