This week, excerpts and early copies of "Fire and Fury: Inside the Trump White House" began to circulate among newsrooms, revealing bombshell claims by author Michael Wolff about President Donald Trump's first year in office.
On Thursday, a lawyer for Trump demanded the author and publisher stop releasing material, retract what had already been released, and apologize. Instead, publisher Henry Holt & Co. bumped up the book's publication date up four days from Jan. 9 to Jan. 5, citing "unprecedented demand."
Friday, the book held the No. 1 spot top on Amazon's best-sellers list in books.
"There has been increased interest in this title over the last 72 hours, with the book sitting on the top of our Best Sellers lists for Books, Kindle Books, and Audible," a representative from Amazon tells CNBC Make It Friday.
Here's a look at how best-sellers lists for books really work.
The rankings for Amazon are calculated roughly every hour from data on book sales, but the factors considered by the e-commerce giant's algorithms remain largely a mystery.
"It is like the most closely guarded secret in the universe," Ellen Geiger, vice president and senior agent at Frances Goldin Literary Agency, tells CNBC Make It.
While it isn't clear exactly how many copies of a book must be sold to break into a slot on the list, a 2013 study of Amazon's best-sellers list for a two-week period by Publishers Weekly found that "a title in Amazon's top five averages 1,094 print copies sold across all channels, including other retailers, on a typical day."
Since Amazon updates its rankings so frequently, "really what it measures is velocity of sales ... over a short period of time rather than an absolute number of sales over a longer period," says Caroline Eisenmann, an associate agent at Frances Goldin. "What it reflects is how a book is selling relative to the other books on Amazon during any one time."
Still, that No. 1 slot in books is certainly an indication of a buying spike.
"If a book has cracked the top 100 and and particularly the top 20 and stays there — the duration is a huge part of it, if it stays there for a few days — that is generally a very strong sign that it is going to be a New York Times Best Seller and that it is going to start showing up on other lists," Eisenmann says. "To hit that top slot is huge. It means that a book is selling hugely during the period it is there."
Currently, the holder of the highest-selling nonfiction release is Hillary Clinton's "What Happened," which sold 300,000 copies in its first week, according to publisher Simon & Schuster, as reported by Fortune.
The New York Times
In contrast to Amazon, The New York Times Best Seller list is updated every week.
Rankings there are determined by book sales reported to The Times by retailers across the country, the Times' methodology states. But, there is "no exact number" of sales that will land you on the list, according to a representative for The Times.
Gathering data from multiple book sellers is a key difference between The Times' list and Amazon, Geiger says.
"The secret to cracking the New York Times Best Sellers list is that they only compile the list based on certain stores that report their figures," she explains. "The first question any book lover should ask when you go into a book store is, 'Are you a New York Times reporting bookstore?'"
If popular in the right stores, the number of book sales needed to land on the list might be less than you would think.
"Depending on the composition of the overall list, it is possible to crack the New York Times Best Sellers list with 1,000 to 2,000 books per week," she says.
"There are a few books that sell a gazillion copies — Stephen King, John Grisham, James Patterson — and then, everybody else."
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