Estimating Kindle Sales From Amazon Rankings

by Brandilyn Collins
Brandilyn Collins is a
best-selling author of nearly 30 books. She is best known for her Seatbelt
Suspense®–fast-paced, character-driven suspense with myriad twists and an
interwoven thread of faith. She also writes insightful contemporary novels,
often laced with humor. Brandilyn is a frequent teacher and keynote
speaker at writers conferences. You can read the first chapters of all her
books on her website.
She loves to interact with readers on Facebook.
On Twitter she’s @Brandilyn.
One of the things that frustrated me most about being traditionally
published was the lack of sales numbers. By the time an author receives a
royalty statement, the numbers are months old and aren’t broken down enough to
be very usable. Meanwhile authors are trying to boost sales with their own
marketing. But without immediate numbers, how do you know what works?
With indie sales it’s completely different. Indies can track
sales daily at all the different venues: Amazon,
Barnes & Noble, Kobo, Apple, etc.  When I run an ad (say, $25 to be Book of the
Day on Indie Author News) or boost a post on Facebook, I can immediately see
how well it worked.
For trad pubs wondering how a book is selling, about the
best you can do is follow your ranking on Amazon. A better ranking (better = a lower number, with #1 being the top) means
you’re selling more books, right? But how many?

Trad pub pals, this post is for you. Please note: I’m going to be talking about digital sales here, not paper copies. 

Amazon rankings are arcane, indeed. Primarily they are fueled
by current daily sales of a book. But it’s more complicated than that. For one
thing, if overall Kindle book sales rise—say between Christmas and New
Years, when folks are buying like crazy to stock their new ereaders—obviously
it will take more sales to reach a certain ranking than in a normal month.
Further, rankings are also partially fueled by past recent sales. And every so
often—approximately between 30 and 60 days—Amazon seems to reset its rankings.
Here’s how one indie author explains it: “Say I run an ad on BookBub,
selling my book for 99 cents, and it sells 1500 copies in two days. Then it
goes down to selling only 20 or so at the regular price. I would know from
previous experience that this number of daily sales usually equals around a 6000-7000
rank. But because of the 1500 sales boost I am ranked between 3000 and 4000 for
the rest of the month. At some point the reset comes, and the ranking drops
like a stone, back to the 6000 or 7000 mark—even though I’m selling the same
number of books a day.”
So estimating daily sales of an ebook based on its
Kindle ranking is certainly not precise. There are some tools designed to help.
The kdp calculator is one, but I find the estimated spread too wide to be of
much use, especially for a trad pubber trying to calculate how much royalty he/she
is making on an ebook per day. In his very helpful book Let’s Get Visible, David Gaughran
lists a chart of Kindle rankings and approximately how many sales they represent a
day. (If you are an indie or hybrid author you should buy this book.) However,
that listing is now a year old. As David admits, the rankings of one book
against others obviously shifts as more books come into the system.
I’m not a mathematician. I can’t give you some
astounding formula for perfect calculation of your sales. But I can let you see
a list of sales-to-rankings I’ve compiled. These are from digital sales of my recent
release, Sidetracked, plus sales from some savvy indie authors kind enough
to share their data. I hope for you trad pubbers that looking at this list will
give you a good estimate of your ebook sales.
In this list the first number is daily ebook sales. Numbers
to the right of the equals sign are the day’s ranking. (BTW, If you’re
constantly refreshing that browser on the day of a big promotion, know that rankings
and sales can lag an hour or two.) Remember these data come from numerous ebooks
and on different days. The variations in ranking for the same number of books
sold on a given day show you how the list can fluctuate.

Trad pubbers, I hope your study of these sales-to-ranking patterns will be helpful to you. Fellow indies, happy daily tracking.


If you haven’t read my new release, Sidetracked, yet–where have you been? You’re missing out on a great story. It currently has 65 reviews, with a 4.9 ranking on Amazon. In fact, it’s ranked #2 in the Top Rated List for Christian suspense. Even better–it’s now on sale for $2.99, but only for a few days. If you’ve already read Sidetracked, now’s a good time to gift the ebook to a friend on Amazon. Or get it on the Nook, iTunes, or Kobo.