Indexing on Amazon Explained: How Amazon Actually Learns Your Book 

If you’ve ever uploaded your book to Amazon, filled in all the boxes, poured over your keywords and categories, hit Publish… and then thought, “Now what?” — you’re not alone.

A lot of authors think that once they’ve set up their metadata (title, subtitle, keywords, categories, description), Amazon will just magically start putting their book in front of the right readers.

I wish it worked like that.

The truth is:  Your metadata tells Amazon what your book should be.  

But it’s your readers who teach Amazon what your book actually is.

That learning process is called indexing. And understanding it is one of the most important steps you can take if you want steady, long-term book sales — not just a little spike on launch day.

Let’s break it down in simple terms.

Think of Amazon as a shop assistant

Imagine someone walks into a bookstore and asks the shop assistant: “I’m looking for a cozy mystery set in a small town, nothing too dark, with a female lead and a bit of romance.”

Now, this shop assistant has never seen your book before. But you happen to be lurking by in the fantasy department (with a copy of your book in your hands) when you overhear this. So you step up and say, “Hey, my book is a cozy mystery! Small town, female lead, light romance!” That’s your metadata. You’re telling the assistant what your book should be shelved as.

So the assistant pops your book on the “cozy mystery” shelf and starts suggesting it to people asking for cozy mysteries.

At first, the assistant is just guessing based on what you told them.

Then the customers come in.

Some see your book on the cozy mystery shelf, pick it up, and buy it. Others glance at it and move on. Maybe a few leave reviews.

The assistant pays attention.

Over time, they realise:

– People who love suspenseful mysteries buy your book more often.

– People looking for light, fluffy cozy mysteries don’t.

– Readers who enjoy small-town thrillers seem to stick with it, leave reviews, and often go on to buy book two.

So the assistant quietly shifts your book from “cozy mystery” to “small-town mystery thriller” and starts recommending it to that crowd instead.

That’s exactly what indexing is on Amazon.

Your metadata is your initial pitch.  

Your readers’ behaviour is the truth about your book.  

Amazon watches, learns, and adjusts.

What actually builds indexing?

Let’s strip away the jargon and talk about what really matters.

When Amazon is “learning” your book, it’s paying attention to things like:

• Who’s clicking on your book
• Who’s buying your book
• Who’s reading it (for Kindle)
• Who’s leaving reviews
• Which other books your buyers are also purchasing

In the beginning, Amazon relies heavily on your metadata because it has no data yet. But as time goes on, it leans more and more on what your readers do.

That’s why two books with very similar keywords and categories can perform completely differently. It’s not just how you’ve told Amazon to see your book. It’s how your readers show Amazon where it belongs.

And here’s the piece most authors miss:  Indexing isn’t built in a week. It’s built over time.

Why consistency matters more than your launch spike

Launches are exciting. Pre-orders, launch parties, social posts — there’s a lot of energy crammed into a short period.

But indexing — the thing that actually drives long-term sales — responds much better to consistent, ongoing activity than to one big burst.

Think of it like this:

• A big launch spike says: “Hey Amazon, something is happening here.”
• Ongoing sales, even if they’re modest, say: “This book is steadily relevant to a certain group of readers.”

Amazon likes patterns. If your book sells a handful of copies most weeks, gets the occasional new review, and has the odd traffic bump from an ad or a promo, that consistency tells Amazon, “People in this niche keep choosing this book.”

That steady activity strengthens your indexing.

In practice, that means:

– Don’t panic if your book doesn’t “take off” in week one.

– Don’t assume your book is a failure if sales slow after launch.

– Do focus on small, sustainable actions:  

•   The occasional ad campaign  
•   Emailing your list  
•   Asking for reviews in a gentle, ethical way  
•   Participating in promotions that bring you targeted readers

Indexing is built brick by brick. Your launch is one brick. The rest are laid over months.

Using reverse indexing to see what Amazon thinks your book is

One of my favourite ways to peek under the hood is by using reverse indexing tools, like the feature in Publisher Rocket.

Here’s what that means in normal language.

Instead of you telling a tool, “Here are my keywords — tell me if they’re any good,” you ask:

> “Here is my book — what keywords is Amazon already associating with it?”

You pop in your book’s ASIN, and the tool pulls back the phrases and keywords that Amazon is currently linking your book to.

That’s like asking the shop assistant:

> “When people come in asking for a book like mine, what sort of things are they saying?”

Sometimes the results will reassure you:  

“Yes, Amazon sees my book as a clean fantasy romance with dragons. Good.”

Other times, you might get a surprise:  

“Why on earth does Amazon think my cozy romance is linked to dark mafia thrillers?”

When you see that misalignment, you can go back and adjust:

– Your keywords, so they better reflect your real content  

– Your categories, so you’re in the right neighbourhood  

– Your description, so you attract the right readers and gently deter the wrong ones

You’re not trying to trick Amazon. You’re helping it understand the book you’ve actually written — which in turn helps it put your book in front of the readers who will genuinely love it.

The best tool to check your indexing is Publisher Rocket – available here.

So, what should you do next?

If you’re feeling overwhelmed by all this, take a breath. You don’t need to fix everything at once.

Here’s a simple way to move forward:

1. Make sure your metadata is honest and accurate.  
2. Focus on gradual, ongoing activity — not just a big launch week.  
3. Use reverse indexing to check what Amazon currently “thinks” your book is about.  
4. Tweak and refine over time, based on what you learn.

Indexing is not about being perfect from day one. It’s about giving Amazon a clear starting point and then letting real readers help fine-tune where your book belongs.

And if you’d like support as you navigate the whole publishing process (not just indexing!), you’re very welcome to join us inside the Publish with Purpose membership. You’ll get ongoing support, live Q&A calls, access to our video trainings anytime, and step-by-step guidance through each stage of your publishing journey.

You can start with a free trial here:  www.publishwithpurpose.com.au

When you’re ready, come watch the video, explore the tools, and let’s help Amazon truly learn your book — so it can find the readers it was meant for.

Kathy Shanks

Turtle Publishing was founded in 2020 by self-employed designer and happily married mother of two, Kathy Shanks. With 20 years of design experience and having created her own journal in 2019, where she subsequently believes that the ‘universe started throwing books at her’, Kathy is passionate about creating designs that convey the right emotion and ‘vibe’ to the right audience and specialises in budget friendly publishing solutions.