In a piece of what can best be described as meta-marketing, Doubleday promoted The Wisdom of Crowds (on sale May 25) with a contest intended to prove the title's thesis: that large groups of people make better decisions than individuals, even when those individuals are experts.

To test the hypothesis of the book by New Yorker business columnist James Surowiecki, Doubleday invited employees of five independent booksellers, with 15 store locations, to guess how many copies of the house's bestselling novel The Da Vinci Code would sell at all branches between December 1 and December 31. The person from each store whose guess came closest would win a $100 American Express gift certificate.

If the thesis of The Wisdom of Crowds held water, then the median answer would be closer to the correct response than the individual answers. And on the whole, the many were indeed smarter than the few. The 15 stores sold 2,890 copies of The Da Vinci Code, not far off the median answer of 2,646 copies. Still, a handful of the 193 participants from Olsson's Books and Records, University Bookstore, Tattered Cover, Book People and Stacey's placed bets that came closer to the actual number than the median. But that may have been because the median was thrown off by a few respondents who probably misunderstood the question (like the unnamed participant who guessed one million copies). In any case, the utility of Surowiecki's theory rests on the fact that while there are generally a few smarter-than-the-crowd individuals, it's often difficult to predict who they will be.

Margaret Vickers, trade backlist buyer for Stacey's Bookstore in San Francisco, thought the contest was a smart marketing idea—and not just because she won. "That contest got a lot of employees involved," she said. "It was great for building grassroots enthusiasm."

The contest is part of a marketing push geared to helping The Wisdom of Crowds straddle the business and general trade markets, just as Malcolm Gladwell's The Tipping Point (Little, Brown, Feb. 2000) did. The potential to reach both markets is reflected by the variety of publications planning to review The Wisdom of Crowds, ranging from Elle to Harvard Business Review. After a four-city pre-publication tour, Surowiecki will appear on Today on the on-sale date. From there he embarks on an eight-city reading tour.

Whether or not The Wisdom of Crowds reaches Tipping Point heights, independent booksellers didn't need the bookseller experiment to learn Wisdom's lesson. As Doubleday publicity manager Nicole Dewey pointed out, "Independent bookstores already have a method of acting on the wisdom of crowds: It's called Book Sense."