The Best-Seller List is one of the most fascinating and confusing aspects of the book publishing industry. Almost every time we work with a business book author, a conversation comes up about what being on the list means, and how a book can “hit” it. Having a best-seller can really make an author’s success and drive future sales of the book, and future sales of future books…while at the same time many truly wonderful books will never hit the list.
Sunday’s New York Times had a great article about the its Best-Seller List: “Books for the Ages, if Not for the Best-Seller List” by Clark Hoyt. One question we’re often asked is, How many books do I have to sell to make the list? It’s a tough question to answer because the list is such a complicated beast. Booksellers report their sales in different ways, long-standing best-sellers might be taken off the list to give new books a chance to shine, and even books with very high sales numbers might not make the list because of timing–especially when several big books hit the shelves at the same time. Hoyt explains some of these discrepancies:

There are usually differences between the Times list and others, often, apparently, because of timing or because different lists put books in different categories. USA Today, for example, combines all books — fiction, nonfiction, paperback and hardcover — into a single list. No book is ever banished as an “evergreen,” meaning “Night” can be found at No. 129 this week, nine spots below “The Official SAT Study Guide.” But “for what The New York Times is doing,” Sorensen said, “it’s very accurate.”
Why banish a book just because it has been around a long time? The Times wants a list “that’s lively and churns and affords new authors the opportunity to be recorded,” Hofmann said.

I encourage you to check out the article if you’re at all interested in how certain books end up on that list in Sunday’s book section of the newspaper. While the article doesn’t go deep into the science of the bestseller list, it does show it has been set up to generate an interesting list that is a reflection of real sales and consumers’ current interests.
http://www.nytimes.com/2007/10/21/opinion/21pubed.html?_r=2&oref=slogin&oref=slogin