1

How can I estimate how many copies of a book are being sold on Amazon? I presume there is some relationship between the rank of a book and its number of copies sold.

For example, "The C Programming Language", a perennial classic for programmers is listing at #1,506 on Amazon Best Sellers. I estimate this book probably sells at least 10,000 to 20,000 copies per year even though it is 30 years old. By making a number of such estimates and fitting it to a logarithmic curve I could probably figure out the function between Amazon rank and total sales, however, I assume someone else has already done this. Am I right?

1

A best selling romance author, Theresa Regan, somehow came up with estimates based on rank:

Amazon Best Seller Rank 50,000 to 100,000 – selling close to 1 book a day.

Amazon Best Seller Rank 10,000 to 50,000 – selling 5 to 15 books a day.

Amazon Best Seller Rank 5,500 to 10,000 – selling 15 to 25 books a day.

Amazon Best Seller Rank 3,000 to 5,500 – selling 25 to 70 books a day.

Amazon Best Seller Rank 1,500 to 3,000 – selling 70 to 100 books a day.

Amazon Best Seller Rank 750 to 1,500 – selling 100 to 120 books a day.

Amazon Best Seller Rank 500 to 750 – selling 120 to 175 books a day.

Amazon Best Seller Rank 350 to 500 – selling 175 to 250 books a day.

Amazon Best Seller Rank 200 to 350 – selling 250 to 500 books a day.

Amazon Best Seller Rank 35 to 200 -selling 500 to 2,000 books a day.

Amazon Best Seller Rank 20 to 35 – selling 2,000 to 3,000 books a day.

Amazon Best Seller Rank of 5 to 20 – selling 3,000 to 4,000 books a day.

Amazon Best Seller Rank of 1 to 5 – selling 4,000+ books a day. 

Note that if we apply this formula to my example, "The C Programming Language" that would 100 books a day, or 36,500 books per year for K&R. My guess is that this is somewhat high, but in the right general ballpark based on my knowledge of that book and its market, so Regan's estimates may be roughly correct.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy