I refer you to the TitleZ page because Amazon has no explanation. There was a page that explained sales rank at one time, but it's empty now. TitleZ also offers a service that gives long-term average ranks, which could be of interest to authors who cannot readily get sell-through data from their publishers. (The service is at present still in beta.)
Wednesday, October 22, 2008
What's a Good Sales Rank at Amazon?
As most writers have noticed, Amazon offers a sales rank with each book's listing; it's at the end of the Product Details section (the listing with publisher, publication date, number of pages, etc.) I've just looked at the Canadian listing for On the Way to the Web, and as I write this it is ranked 2,433. Which means that only 2,432 books are selling better. It also ranks number 1 in the category of Internet History.
In a world of hundreds of thousands of books, that's pretty good. In fact, this site (TitleZ) says that it's a "very successful book," or that any book ranking between 1,001 and 10,000 is very succeseful. (Books ranking 1 to 100 are "best-sellers.") That judgment only maintains if the number is an average; a book may jump to 942 (as On the Way to the Web did one day), but that could be a spike in response to a review or media mention. A given rank doesn't provide useful data; you must take a look at overall averages--by week, month, quarter--to get a good feel for how well the book might be doing, comparatively.
The data are for Amazon sales only. There is no correlation between sales ranking and the number of copies sold. A service called BookScan will give you precise info on chain and other sales. Depending on who you're talking with, BookScan gives you 60 or 70 percent of total sales.