Is the latest bestseller simply the product of clever marketing or
has it truly permeated society? Will its popularity wane as quickly
as it appeared or will the book be a classic for future generations?
Though these questions seem to lay outside the realm of science, scientists
can actually obtain deep insights into these issues by using the tools
of statistical physics, which can predict the rates at which certain
events occur, such as the number of aftershocks following a major earthquake
or the number of large avalanches in a given sandpile.
Using a unique database of the Amazon.com rankings of book sales,
scientists (Thomas Gilbert, UC-Berkeley, 510-642-5295, firstname.lastname@example.org)
followed the chart histories of books that reached the top 50 in sales.
The researchers found that the bestsellers generally reach their sales
peaks in one of two ways, which they classify as "exogenous shocks"
(e.g., a rave review in the New York Times) and endogenous shocks
(e.g., word of mouth). An endogenous shock appears slowly but results
in a long-lived growth and decline of sales owing to small but very
extensive interactions in the network of buyers.
For example, "The Divine Secrets of the Ya-Ya Sisterhood,"
reached the bestseller lists two years after it came out (and without
a major marketing campaign) by making the rounds of book-discussion
clubs and inspiring women to form "Ya-Ya Sisterhood" groups
of their own. In contrast, an exogenous shock (rave review) appears
suddenly and propels a book to bestseller status; however, these sales
typically decline rapidly, much more quickly than those that made the
charts via word-of-mouth.
In either case, single triggering events (e.g., a mention on Oprah)
appear to have much less effect on the sales history of a book than
the actions of interconnected groups of people, who may pick up the
book after multiple conversations with acquaintances or by hearing about
the book secondhand or by remembering a friend's recommendation months
or even years after the book comes out.
According to the researchers, marketing agencies could apply their
method of classifying and analyzing bestsellers to measure and to maximize
the impact of their publicity on the network of potential buyers. (Sornette,
Deschatres, Gilbert, and Ageon, Physical Review Letters, 26 November