Amazon Rankings
I thought I would prove immune to Amazonarankitis, but alas, I have fallen victim to its disease. I check where my novel is ranked on Amazon more than once (ha! understatement!) a day. Then I got to thinking: how much does the Amazon ranking tell me about sales?
Being the geek I am I looked into this. For all the similarly afflicted, I'm going to share.
First, the obvious: Amazon.com rankings are like golf scores. You want a low number.
Second: only the top 10,000 books have their rankings recalculated hourly, and that's in comparison to the sales of the other top 9,999 books. Books between 10,000-100,000 in rank are recalculated daily.
Here's an estimate, provided by Dimitri at Civil War Bookshelf.
Rank / Copies per day
1 / X
10 / 100
100 / 30
1000 / 10
10,000 / 2 (11 copies every 5 days)
100,000 / 1 copy a week
1,000,000 / around 15 total, depends on pub date
2,000,000 / around 2 total, depends on pub date
It builds upon the chart and algorithm work of Morris Rosenthal (who uses too much math speak for me to follow well).
So, if your book is ranked, say 17,381, it means you're selling approximately 2 copies a day. Yes, less than that but let's aim for whole numbers, shall we?
This means you're never going to earn out your advance and earn royalties and be able to quite your job. Kidding! Kidding! Excuse me, but there are 6,380 in the year, yes? That's a relief.