Every Sale Helps: Amazon Analysis

I just discovered something cool about Amazon sales rank. We already know that your rank is based on current sales from that day, week, and month, but did you know that all books by an author have the same boost in rank?

Check this out: I have three books available on Kindle. My bestseller “Tumbler” was released a year ago and sells for $2.99. It hovers at around 50-75k in sales rank. My second book “The Hidden Institute” is very new (priced at $4.99) and has far less of a following. It generally hovers at around 75-100k. My third book, a short story collection called “The Danny”, costs only $0.99 but is the newest of them all, and has the lowest sales. It is in the 200k range.

Earlier today (see point 1 on the graph) I made the first sale in several hours. That made a big drop in my sales rank, pushing it from 72k down to 35k. Now look at the other sales at the same time. . . no change. They continue to rise at the same level. So, when there is only one new sale, there’s a big change for the first, but little change on the others.

Now look at point 2. Clearly, there has been another sale, but this one has far less change. Whereas the previous sale dropped our rank by 37k, this one only dropped by 15k. The interesting thing to note here is what happened to Hidden Institute and Danny at the same time. As soon as Amazon realized that there were multiple sales in a short time, they halted the rank drop for both of my other books.

Now, take a look at point 3. By this time, Amazon has realized that there were several sales within the same timeframe. Note how the angle of growth on Tumbler’s rank started to flatten out. At this point, Amazon isn’t ready to make Tumbler start rocketing back up because of sales. (It’s worth noting that, as time goes on, the rank starts growing at it’s original rate. If you don’t make consistent sales, the rate starts to move faster.)

But again, the cool thing to note is what happens to Hidden Institute and Danny at the same time. Their growth flattens out the same way that Tumbler’s did.

So, a lot of this is just general chart fun. What does it actually mean for the writer?

For me, it means that I should be writing. Every time I make a sale, I don’t just help the rank of that book, but all the books I’ve written. Therefore, the more books you have, the more sales (overall) you will make, and the more you will help all of your back catalog.

So the lesson is pretty obvious. Get back to writing.

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  1. Interesting info, Brand. I’m a bit of a data nerd, especially when it comes to correlation and causation. What might be interesting to see, if you’re interested in sharing, is the correlation between your sales rank and the number of copies sold.

    Google makes a free kick-ass little tool that help uncover hidden correlation. No idea if it’ll work in this case or not, but give it a shot: http://www.google.com/trends/correlate/

    And yeah, keep writing and releasing. That’s a common theme everywhere!