How many book sales equal an Amazon bestseller?

(Sorry, borrowed this article from Salon.com . I would have linked straight to the article but they have popups on their site and I don’t trust those.)

SUNDAY, MAR 10, 2013 03:31 PM EDT
How many book sales equal an Amazon bestseller?
Publisher’s Weekly says it may not be that many
BY ALEX HALPERIN

Amazon sales figures are among the best kept, and most sought after, secrets in the publishing industry. The list updates hourly but Amazon, the biggest book retailer in the country, refuses to share data on what level of sales correspond to a coveted spot at the top of the list. (The New York Times’ bestseller list, still arguably the most influential in the country, is also cagey with its metrics.)

In an article today, Publishers Weekly tried to reverse engineer a book’s sales on Amazon by tracking its position on the bestseller list. The conclusion, which is couched in plenty of caveats, is that reaching the top of the Amazon list only requires about 300 sales through the site per day. It’s not a result that will cheer the always beleaguered publishing industry.

Here’s how the experiment worked:

We looked at Dark Horse’s The Legend of Zelda: Hyrule Historia, a 300-page collection of historical information, concept art, and chronology of the famous Nintendo video game series. We charted the book’s ranking on Amazon, and during the weeks ended February 24 and March 3, it sold 8,573 copies and 6,128 copies, respectively, at outlets that report to Nielsen BookScan. During that two-week span, Hyrule Historia never fell out of the top five on Amazon’s print ranking. For the week ended March 3, the book sold 6,128 copies at outlets that report to BookScan (which covers about 80% of print units). To account for the units not reported to BookScan, we added 20% to its total of 6,128, which equals 7,353. Based on that total, the book sold, on average, 1,050 copies per day, which means that Amazon sold no more than that number of units on any given day. But because Hyrule Historia is available through other retailers like Barnes & Noble, Target, and even video game chain Gamestop—the book is also sold out on Walmart.com—the realistic estimate is that Amazon sold roughly 30% of the 1,050 copies, or 315 copies per day, on average.

In a separate article in the trade publication, publishers are banding together to try and stop Amazon’s bid to buy the Internet domain name “.book.”

Alex Halperin is news editor at Salon. You can follow him on Twitter @alexhalperin.