I was recently asked what amount of book sales lead to rankings averaging 100, 1000, etc. Put another way, how many books would an author have to sell in a given month to have an average ranking for the month of 1000? So, I dug back into the book sales estimates and came up with 3 examples.
This is based on data on Amazon.com only. For Amazon.co.uk, you can roughly estimate that it takes only 80% of the number of sales on Amazon.com to equate to the same average ranking. For Canada, Germany, Japan, and France, it is approximately 65%, though there is not enough data in NovelRank to depend on that percentage.
Sales Rank Average: 1000 (paperback, hardcover, etc)
Example book: Pursuit of Honor by Vince Flynn
About 250 copies were sold to maintain a sales rank around 1000. That makes it 8 books per day, with a sale occurring every 3 hours, or maybe 2 books selling every 6 hours! Either way, this is a very healthy sales rank.
Sales Rank Average: 100 (paperback, hardcover, etc)
Example book: The Elegance of the Hedgehog by Muriel Barbery and Alison Anderson
Almost 2000 copies were sold in May to garner an average sales rank of 106. That is a selling rate of at least 3 books per hour! What is likely is that this number may actually be notably higher, as sales rank changes are less defined or varied at this level, however it is hard to verify.
Sales Rank Average: 2000 (Kindle Edition books)
Example book: In the Mood by Ellen Fisher
Selling approximately 500 kindle books a month will lead to an average sales rank around 2000 for your book. To do this, you need to sell about 16 books a day or 1 book every 90 minutes.
Note: This Kindle sales estimate is based upon real sales data from Amazon DTP provided to me from the author. NovelRank is currently underestimating for Kindle Edition books with a Sales Rank below 4000.
Hopefully this is enlightening for you. Remember, the strength of NovelRank is not in raw numbers; You will get those from your publisher eventually, but rather in understanding the fluctuations so you can attribute your best marketing efforts to the strongest sales bumps in near real-time.
Disclaimer: NovelRank book sales estimates are based on fluctuations of sales rank and thus there are many factors (another blog post coming soon) that can cause for more sales to occur than is estimated by NovelRank. These numbers are estimates.