Visit National Public Radio at its headquarters in Washington, and you might think you have accidentally wandered into a corporate headquarters. The network, which once operated out of a cramped basement, today fills a sleek seven-story building with a lobby curved like a radio wave. Its studios feature the latest digital sound gear. Executives, if prodded, talk about "branding," "revenue growth" and "audience fragmentation." They speak such words softly--NPR is, after all, a not-for-profit organization whose member stations constantly beg listeners for contributions. But it's getting harder to keep its success a hush-hush affair.
After nearly going bankrupt in the...