One of the most convenient “real time” views of how a book is doing is to check out Amazon’s sales rank. It’s simple (the lower the number, the better the sales), it’s convenient (just a click away), and it’s empirical (gotta love those numbers). Alas, as Aaron Hierholzer says, “the Amazon sales rank is a fickle mistress.”
Hierholzer sees the ranking as “more like a popularity contest than the litmus test for a book’s success.” Not only does Amazon’s secret formula include complex algorithms, there are varying rates of decay built in, predictive curves, different refresher rates and a part played by historical sales. (You know, figures don’t lie but liars figure.) More than hard facts, the ranking, in Amazon.com’s own words, is meant to be merely “interesting.”
Some folks have tried to extrapolate what the rank actually means in terms of sales. Morris Rosenthal provides a chart that estimates a rank of 100 meaning 100 books sold per week on Amazon, while a rank of 100,000 means about 10 are sold a week. Brent Sampson estimates about the same for a rank of 100 but more like 1 a week for a rank of 100,000. Still other observers (such as Rampant TechPress) offer their own calculated guess.
Since it is essentially impossible to know what the ranking means or why it goes up or down when or as much as it does, authors and publishers are most likely better off putting energy into other things than trying to directly influence the rank. Personal appearances by the author, print and electronic publicity, word of mouth recommendations, effective direct marketing–all the normal things we do day in and day out are what will make a difference.
Amazon sales rank? Doesn’t mean much, but it sure is fun.