This week, we decided to do a post on Amazon best seller ranks–the number that is directly linked to book sales but proves to be difficult for authors to evaluate.
While the way Amazon best seller ranks are calculated is not publicly revealed, this number actually ranks the books in order of sales through the Amazon web site. I.e., the most sold book will have rank #1, and the least sold will be in the 6 million or so range, directly corresponding to the number of books available for sale through Amazon. The good news is, if your book has an Amazon sales rank, it means somebody bought at least one copy through Amazon. If your rank is steadily in the top 10 for a few months, you are probably going to get a very hefty paycheck. But that is not very helpful, is it?
Over the year or so we have been selling e-books through Amazon, we have accumulated data comparing the number of book sold (or downloaded for free by Amazon Prime members through KDP Select program) to the best seller rank showing on the book information page. This number can be found down the page after the book description, under the Book Details, and looks something like this:
- File Size: 553 KB
- Print Length: 272 pages
- Simultaneous Device Usage: Unlimited
- Publisher: Dragonwell Publishing; 1 edition (December 18, 2012)
- Sold by: Amazon Digital Services, Inc.
- Language: English
- ASIN: B00AQNG78K
- Text-to-Speech: Enabled
- X-Ray: Not Enabled
- Lending: Enabled
- Amazon Best Sellers Rank: #48,558 Paid in Kindle Store (See Top 100 Paid in Kindle Store)
In this example, the Best Sellers Rank tells us that this particular book is currently #48,500 or so on the list of sellers through Amazon, but does it actually tell anyone who many copies this book sold? Actually, it does, to some extent.
To make the top 100 Paid in the Kindle store, a book needs to sell about 1,000 copies or more in one day. Its exact placement then will depend on the other sellers in this ranking. For example, a recent article by Publishers Weekly analyzed that selling 6,000 or so copies per day can land a #1 ranking and keep the book in the top 5. If no more copies are sold (which rarely happens for this kind of books, but could, if the rank was achieved through a short-term promotional discount), the ranks will slowly taper and reach 100,000-200,000 within a week or so, and will deteriorate further after that. However, this rarely happens to the top 100 books, so if you have ever seen your book at this kind of ranking, chances are your book is a real success.
Amazingly enough, the ranks going down from there fall in a perfectly correlated way. The sales of 100 books a day will give you a rank of 1,000 or less, 30 books a day will hover around 3,000 or so, 10 books a day will keep the rank of about 10,000 and so on. If you steadily sell one book a day without fail you will have a rank around 100,000. In addition, if you keep daily track of your ranks, you can always see a boost after each sale, since the ranks are frequently updated, especially for books with the rank of 100,000 or above.
While you may find detailed charts and algorithms in other places on the web, we found that following this simple estimate can enable authors to maintain a fairly accurate data about their sales through Amazon, if these authors are committed enough to do daily rank checks.
These numbers concern e-book sales only, since other platforms and formats cannot be easily tracked in almost real time. And, one can in principle use these numbers further to calculate royalties due. For example, if your contract is for 50% of the e-book revenue, a book with a cover price of $9.99 will bring your publisher between $3.50 and $7.00 (depending on the distribution channel) and you can make $1.75 to $3.50 per each sale. For a book with 100,000 rank this would be your daily income, rounding up to about $1000 per year.
Of course, there are always other venues, including print sales and other e-book retailers.