The Amazon Best Sellers Rank is probably one of the numbers that is the least understood.
In the calculation of this number there are a lot of factors that are taken into account:
• Your current and most recent sales
• Your past sales
• The sales rate of your book. (=How many sales in a certain period)
• The total period that they have been for sale (The publication date)
And probably a whole lot more. And all these factors weigh in for a certain amount in the overall calculation of your Amazon Best Sellers Rank.
The Amazon Best Sellers Rank appears on the detail page of every book that has sold at least ONE copy.
What does Amazon themselves say about Author Best Sellers Rank?
“While the Amazon Best Sellers list is a good indicator of how well a product is selling overall, it doesn’t always indicate how well an item is selling among other similar items. Category and subcategory best seller lists were created to highlight an item’s rank in the categories or subcategories where it really stands out.
We choose a few of the most popular subcategories in which the item has a high ranking in relation to other items in that subcategory, and showcase the item’s rank on the product page. As with the main Amazon Best Sellers list, these category rankings are based on Amazon.com sales and are updated hourly.”
Well, that doesn’t tell us much HOW they really calculate that number.
The sales rank is calculated hourly, but the data that is taken into account is over the last 24 hours. Recent sales weigh in more, and historical data weighs in less.
Do I know the exact formula? No. Does anybody know? Probably some Amazon employees. Anyway, I’ve never seen an article or blog post or help page showing the exact formula. But this is the same discussion as “How does Google rate their pages”. It is known that they use over 200 parameters to calculate a Page Rank. But no one seems to know the exact formula. I once wrote a blog post about this. You can read it here: The Secret Google Algorithm Finally Revealed!
But in such a case, you can use the black box approach. Feed something in and see what comes out. And because there are thousands of authors writing about their sales rank and sales, you can than draw some conclusions about what probably is going on behind the scenes.
So here are a number of findings:
Relationship between sales and overall sales rank.
By analyzing the figures of authors, their sales and their sales rank (and of course your own figures), you can get some ballpark figures, how sales influence your sales rank.
The higher you get in this table, the more sales are involved and the more reliable the figures. And vice versa. So for a book at the bottom of this table, it may sell one day 1 copy, the next day 2 and the next day 0.
When your book is in the 50.000+ range, the sales rank will vary wildly. One day it may rank on 200.000 and the next day on 300.000 or 100.000. This simply means that the sales are insignificant from your book AND competing books in that range. Your book sells 1 copy and your competitors none: Your sales rank may bump up 100.000 or more. And vice versa. Your book doesn’t sell one copy on a certain day, and a competitor book sells 1 copy, your sales rank may go down with 100.000.
Conclusion: As long as you’re on the bottom of this list, don’t worry too much about your sales rank. Wait till you get to the 100 sales a day mark (if you ever get there), and then things start to be much more reliable and interesting.
Only real sales are taken into account. Free downloads don’t influence your Sales Rank.
Because your sales rank is relative to sales from other books in your category, it also means that if due to some external factor everybody in your category starts to sell more, the rise in sales rank may not be as spectacular as you would have expected by just looking at the sales.
Amazon also uses some predictive sales analysis to forecast where your future sales will go. This explains why a newly released book can be ranked higher than a book that was released a year ago. Even when the other book has more total sales. Amazon can predict that this new released book will overtake the ‘older’ book using the sales rate.
However, while your book climbs up the sales ladder, the competition will get tougher. Because the other books have loads of historical sales data. That’s why breaking through the 10.000 barrier is difficult and breaking through the 5000 barrier is even more difficult.
A marketing effort may create a spike in your sales rank. However, if after a couple of days your sales slow down, the historical data from your competitors will start to weigh in more and more, and your sales rank will go down quickly. That’s why it is better to space out your marketing efforts, to maintain a steady sales rank.
When are you a “bestselling” author?
Notice that the sales rank on Amazon is called “Amazon Best Sellers Rank” and not “Amazon Bestsellers Rank”. The wording is maybe not the most appropriate because the “Amazon Best Sellers Rank” is just a number from 1 to over a million. So, any book on Amazon that has sold at least one copy will have a “Best Sellers Rank”.
Now if you’re in a low competition category like “History Books>18th Century”, just a couple of sales can boost you to the top in THAT subcategory. So, you will see something like:
#1 Kindle eBooks>History>18th Century.
Does that make you a bestseller author? Well, it depends on your definition of bestseller. For most people, a ‘bestselling’ author sells hundreds if not thousands of books a day. But if it flatters your ego, you can make a screenshot of your #1 rating in 18th century books, and post it on your blog.
If you want more explanations on Amazon categories, keywords and how to market your book to make more sales, have a look at my book “How to Make Money with eBooks. The Best Collection of Marketing Tactics to Boost Your Sales”.