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 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.

Computers aren’t that good at understanding language in context. 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:

“marine science fiction”

A human looking at that phrase would say, “Okay, this guy is looking for a military science fiction book because the Marines 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 “marine science fiction” about 1,500 times a month into the search box on Amazon.com.)

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 Amazon.com, 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.