How relevant are the Amazon sales reports for your book?

Amazon offers sales reports from Kindle Publishing Direct, royalty reports from Create Space for print-on-demand, and you have sales and author ranks from Author Central.

When I have a new book out, I check every day, a few times a day. Every step up is a reason to celebrate. It’s good for morale and is also deceiving.

It’s my estimate, based on the graphics of the reports, that there are around 3.000.000 books in Kindle format and 8.000.000 books in print-on-demand. Once you sold 2 up to 5 books your ranking goes up to 300.000 – 600.000. That means that only 20% of books listed on Amazon are really bought by readers.

This is the moment when I stopped writing to this post and start searching for an answer online. I had that déjà vu feeling of reinventing the wheel. And I found a really cool tool:

kindle-rank-calculator

With it you can find how many books are sold for a book in the same genre as yours. So, again:

How relevant are the Amazon sales reports for your book?