Categories and Keywords Can MAKE or BREAK Book Sales! How do you know if you are using the right ones? by Richard Hoy, Boost a Book

Categories and Keywords Can MAKE or BREAK Book Sales! How do you know if you are using the right ones? by Richard Hoy, Boost a Book

In my last article, I talked about one of the many cool things you can do with Facebook advertising. This week, I’m going to shift the focus, and talk about something it seems many authors treat casually – picking the right categories and keywords for their books.

What Computers Are Not Good at Doing

Over the years I’ve seen many authors try to be creative with their book titles, using things like:

$ell More $tuff! – Your Guide To More RICHE$

The Amerikan Kommunist

H0w I 3aRNed oNe miLLi0n doll@ars IN unMARk3d b!LLS: Diary of a Kidnapper

HugZ Not DrugZ

Living Your Phantasy Life – A Guide to Happyness

Who Da Thunk It? A Guide to Weird Facts

The thing is, computers don’t understand “creative” like you and I do. Moreover, even if they did, the book buyer would have to type the phrase EXACTLY as written when trying to find the book online. Using something contextually similar, like St. Petersburg for Saint Petersburg, will probably work. But, there is no contextually close phrase for “unMARk3d b!LLS.”

The point is, in order for retailer computers to do their job, the information within them needs to be a precise representation of the books they describe. And, more importantly, the information needs to closely, if not exactly, mirror the terms people are using to search for it.

More on the practical implications of this in a minute. But first, let’s go into more details about categories and keywords.

What Exactly Are Categories and Keywords?

Categories and keywords, part of a larger collection of information called metadata, are what retailers, libraries, and distributors use to index a book so customers can find it. This is especially critical today because most book buyers don’t thumb through a shelf full of books. Instead, they scan categories on a website, or type phrases into online bookstore search engines. If a book isn’t associated with the categories and keywords those buyers are clicking on or typing in, it greatly reduces the chance of that book being found.

In other words, the modern bookstore is essentially a giant computer database. Such systems require one to be precise about describing a book in order for people to find it.

The Birth of BISAC Categorization

Let’s take a trip back in time.

It is 1975. President Ford is falling (down the stairs of Air Force One). Disco Duck is rising. And, the Book Industry Study Group comes up with BISAC – an acronym for Book Industry Standards and Communications. BISAC is essentially a categorization system for books, which is still very much in use today.

When a publisher sets up a book in a distributor’s system, it assigns the book up to three BISAC categories. That way, when the book gets to the bookstores, the bookstores know what shelf on which to put the book. For many self-published authors, assigning BISAC categories are as far as they ever go with categorization.

Now, fast forward to 1994. A fledgling comes along. They are a small book seller on this fad thing call the “Internet” and, of course, they have to conform to the BISAC system, just like a physical bookstore, because the book distributors (Ingram in particular) require it.

Fast forward again to 2006-ish. Amazon is now into ebooks. These ebooks are in Amazon’s own format (a.k.a. Kindle). Amazon seemingly wants to take over the entire book retail industry, and decides to dictate how things are going to get done. So, it builds a separate categorization system for the Kindle side of things.

On top of the Kindle thing, Amazon is now the largest player in the physical book market. And, Amazon has a significant advantage in that it, unlike physical bookstores, can see (in real time) how its customers are searching for books. From this insight, it becomes apparent that the BISAC system, with its measly 4000 categories, is way too confining for Amazon’s customers. So, Amazon builds its own system on top of BISAC, expanding it into what are today about 16,000 categories.

The Practical Implications of Categories For Authors

For authors trying to sell books, it is important to understand two things about categories on Amazon.

First, buyers on Amazon focus on specific categories, especially when it comes to fiction. I sometimes see that fiction authors will pick a broad category, thinking more people will see the book. For example, a writer that writes military-themed science fiction stories might pick this BISAC category:

FIC028000 FICTION / Science Fiction / General

But people who read military science fiction actually look here:

FIC028050 FICTION / Science Fiction / Military

And, if an author did get specific, but left it at the BISAC level, the book would likely end up here on Amazon:

Books > Science Fiction & Fantasy > Science Fiction > Military

Amazon tries to match the BISAC category to its closest category. But, if there is no clear match, Amazon makes a judgement call, and puts the book in a category it thinks is best. (Sometimes, they fail miserably at this, putting a book in a completely unrelated category…but that discussion will need a whole other article altogether.)

Amazon’s category choice can be broad, even though the book might better fit into one of these narrower genres:

Books > Science Fiction & Fantasy > Science Fiction > Military > Space Fleet

Books > Science Fiction & Fantasy > Science Fiction > Military > Space Marine

Which brings me to the second important thing to understand about Amazon’s categories. Amazon has individual best seller lists for each category. Getting in the top 25 on any of those lists gives a book more exposure. And, because those categories are narrow, the number of sales a book needs to get into the top 25 is usually a lot lower. So, it is generally better to categorize narrowly (as long as the book fits that category, of course) as it works in an author’s favor because of the way Amazon compiles best seller lists.

I write “usually” and “generally” because each niche category has a different level of competitiveness. There are manually intensive ways to figure out which category is what, based on sales rank, as well as services that show this data to you for a fee. Authors need to factor in category competitiveness to get the most benefit out of this tactic.

Why Keywords? What Do They Really Do?

Okay, so now we hopefully understand categories and their importance. What about keywords? Why even assign keywords to a book? That’s a good question, Richard. Let me answer it. Okay, please do. Okay, I will.

Remember, earlier I wrote computers aren’t that good at understanding language in context, but humans are really good at it?

Well, the purpose of keywords is to provide a computer with context. Here is an example.

Suppose I like military science fiction but, to find it on Amazon, I use the search phrase:

“army science fiction”

A human looking at that phrase would say, “Okay, this guy is looking for a military science fiction book because the Army is a branch of the military.”

But, a computer takes that phrase literally. It cannot make the connection to a military science fiction genre book unless there is a matching keyword phrase attached to the book.

To put it simply, keywords are the connection between what a human enters into a search engine, and the book records contained within that search engine.

(Believe it or not, people enter the phrase “army science fiction” about 7,000 times a month into the search box on

The Practical Implications of Keywords For Authors

Just like with categories, authors should be narrow with their keyword focus.

I see this mistake all the time:

“dreams”, “God”, “ebook”, “self-help”

People very rarely search for a book using just one word. Single keywords (as opposed to phrases) are not helping an author sell books. These words are too general. When buyers resort to using a website’s search engine, they are doing so with intent. And, the search phrases buyers enter reflect that intent.

Conversely, this is a good keyword phrase:

“Self-help career books spiritual”

It is clear from this phrase that the person entering it into a search box is looking for self-help books, with a spiritual focus, aimed at furthering a career.

And, believe it or not, this exact phrase gets about 4400 searches a month on, though it is highly competitive. If I were advising an author, I’d try to find a less competitive phrase that captures a similar idea.

With fiction keyword phrases, the trick is to find phrases that describe the characteristics of the story.

If you are a novelist trying to figure out keyword phrases, ask yourself:

– What’s the time period of the story?

“Victorian romance”, “Medieval adventure”, “1920s mysteries”

– What are the qualities of the main characters?

“female hero”, “evil twin”, “lovable loser”

– What is the theme of the plot?

“environmental terrorism”, “psychological thriller”, “cozy mystery”

As with category selection, the keyword phrases should always accurately reflect the content of the book.

Take Away Points…

+ Don’t be cute with book titles. Use standard English only (assuming, of course, the target audience is English).

+ In today’s online book selling world, it is always better to put a book in a narrow category versus a broad category.

+ Keywords should be phrases. And, they should match exactly, if not as closely as possible, to the phrases searchers are entering in a particular search engine.

+ When it comes to, all categories and keyword phrases have varying levels of competition. In order to get the full value out of optimizing both for a particular book, one needs to understand these levels of competition. Otherwise, the book doesn’t have a chance of standing out from the crowd.

Involved in Internet marketing since 1995 (when it officially became a profession), Richard Hoy advises on, and helps execute, Internet marketing efforts for solopreneurs and clients of digital marketing agencies. His current focus is search engine optimization for books on Amazon and for local businesses on Google.


Angela is not only the publisher of She is President & CEO of,
a self-publishing services company that has been in business since 1998. Ask her anything.


2 Responses to "Categories and Keywords Can MAKE or BREAK Book Sales! How do you know if you are using the right ones? by Richard Hoy, Boost a Book"

  1. Pingback: Building a Successful Book Selling Model Isn’t Complicated or Mystical. Here’s the secret… by Richard Hoy, |

  2. Pamela Allegretto  August 10, 2019 at 1:04 pm

    Thank you for this comprehensive look into keywords.