PG put a link to this article at the bottom of a prior post but then realized that it definitely deserved its own post.
From David Gaughran:
Amazon recommendations drive millions of dollars of book purchases every single day, and Also Boughts are central to this system, which can lead to panic when they periodically disappear.
Also Boughts play an important role in Amazon recommendations — that process of pairing books to readers like some literary version of Tinder — but the exact role in Amazon’s recommender system can be misunderstood.
So let’s break it all down today, and show you the exact role Also Boughts play in Amazon recommendations, and why you need to protect yours.
- What Are Also Boughts?
- How Amazon Recommendations Work
- Product Connections vs. Similar People
- Also Bought Myths & Benefits
- Personal or Contextual Recommendations
- Also Bought Pollution
- How To Protect Your Also Boughts
- When Gaming The System Goes Wrong
- Takeaway: Amazon Has Been Decoded
What Are Also Boughts?
Also Boughts reflect the other purchases your readers are making, and also influence which readers Amazon recommends books to next. As a result, Also Boughts have become the focus of attention among savvy self-publishers in recent years.
You can view them on any book’s product page on Amazon, where you may have noticed a strip of books usually placed underneath the product description, headlined with “Customers who bought this item also bought.” It looks like this:
The Also Bought strip doesn’t update as frequently as some parts of the Kindle Store, but it usually refreshes twice a week, on Thursday and Sunday evenings, which means they are a relatively up-to-date indication of how Amazon’s system views your book.
Meaning that authors watch them very closely.
Amazon’s system is always trying to determine what kind of products each individual customer is most likely to purchase, so it can make more accurate recommendations. One thing which is super important in this process is the connection between products. People who buy printers tend to buy ink, for example, and recommending a printer-buyer some ink to purchase will elicit a lot of clicks.
But it’s not just obvious pairings like leathers and feathers, Amazon’s system is constantly analyzing what everyone purchases and then using that to predict what they will buy next, in its never-ending quest to maximize sales by crunching All The Data.
The net effect when it comes to authors is this: if your book appears in the Also Boughts of a book in your niche which is selling well, this can lead to a considerable spike in sales. Conversely, if something goes wrong with your Also Boughts, it can lead to a measurable dip.
It was understandable that authors would begin worrying when Amazon seemed to remove Also Boughts from book pages, with some speculating that Amazon would stop recommending books organically and only give visibility to those using Amazon Ads.
But that’s not how the recommender system works. And I can show you exactly what I mean.
How Amazon Recommendations Really Work
Amazon makes millions of book recommendations to readers every single day — both on-site in various slots around the Kindle Store, and by email as well. These recommendations take many different forms.
Some Amazon recommendations are very top-down, but most are either personalized for each individual reader, or contextual — based on what the reader is viewing at that moment, or the place they are in the Kindle Store, or an action they just performed. And all of this is completely unaffected by Also Boughts disappearing from book pages.
Let me give you an example.
During the research process for my book Amazon Decoded, I conducted a number of revealing experiments.
Have you ever noticed what happens when you buy a book in the Kindle Store? Specifically, have you noticed what happens on-screen afterwards? Amazon never misses a trick and as soon as you complete payment, a confirmation screen appears recommending more books.
Amazon is split-testing things all the time, so you may see this play out slightly differently each time you purchase a book, but, commonly, you will see Amazon push the book in the #1 Also Bought slot pretty hard.
(Unless there is an audiobook edition which is Whispersynced, then Amazon will often favor that recommendation instead. It can experiment with other approaches, such as a carousel of books, but this will also be heavily influenced by the Also Boughts of what you just purchased.)
If that #1 Also Bought is also the next book in the series, then Amazon will helpfully flag that it is indeed the next in the series – which can really drive that spillover when you are promoting Book 1, especially if you have also discounted Book 2.
(Assuming your Book 2 is that #1 Also Bought, of course, and that your series metadata is in perfect shape.)
This is the kind of thing that doesn’t happen so much on the other retailers, because they simply don’t have recommender systems quite as sophisticated as the one powering the millions of recommendations Amazon makes every day.
Other retailers do have rudimentary recommendation engines, but Amazon is quite literally years ahead of the competition, and it doesn’t feel like that gap is closing because fundamentally different philosophies are at work.
Link to the rest at David Gaughran