There is no shortage on the market of you-too-can-succeed books; they range from Dale Carnegie's How to Win Friends and Influence People (50 years old last year) to the recently published Are You Positive, by Richard Gaylord Briley. But the works of one Napoleon Hill, 1883-1970, seem to have attained the status of underground classics.

Hill's The Law of Success -- his first book -- came out in 1928. It's a sizable volume, expensive, and not easy to find -- INC. had to order its copy for $39.95 from a small publisher in New Jersey. But none of these obstacles dampens the enthusiasm of John McCormack, CEO of Visible Changes Inc., who says the book is "required reading" for all his managers. Similarly with Hill's Think and Grow Rich (1937), which at least is available in paperback. "I read it 12 times in my first seven or eight years of business," swears Al Burger, founder of "Bugs" Burger Bug Killers Inc. Another fan: Mary Kay Ash of Mary Kay Cosmetics Inc., who found it "very inspirational."

At least Hill aficionados are in good company: The Law of Success includes testimonials from F. W. Woolworth, George Eastman, William Wrigley Jr., and Thomas Edison. "By applying many of the 16 fundamentals of The Law of Success philosophy we have built a great chain of successful stores," writes Woolworth. "I presume it would be no exaggeration of fact if I said that the Woolworth Building might properly be called a monument to the soundness of these principles."