Keywords are an important part of a book's marketing program — they are multi-functional, easy to use, and can help turn book browsers into book buyers, but not every online retailer uses them. We've compiled this short guide to help you understand how and where keywords are helpful so that you can optimize your books' chances of discoverability.

But first, what are keywords and why are they useful?

In the BISG's Revised Best Practices for Keywords in Metadata, a keyword is defined as a "consumer-oriented word or phrase that describes the content, theme, or other relevant aspects of a book product that (1) is used to supplement (but not repeat) publicly displayed data (such as title) and (2) will assist with discoverability (including differentiating among books with similar subjects and themes)."

Essentially, keywords can:

help potential book buyers find books through search engines and on retailer websites;
enhance a book's customer-facing metadata and increase discoverability;
help narrow down a search if, for example, a customer doesn't know the title or author of a book but they do know what it's about or who the main characters are;
expand search results if someone is looking for all the books available on a specific topic or for winners of a certain award;
be used to relate the book to other titles in the case of a spin-off, adaptation, or sequel;
help expand on BISAC subject categories if you want to make the subject more specific; and,
provide synonyms for words that are used in the title, since it's unlikely that a customer's search and the chosen title will match up exactly.

Tips for choosing great keywords

To be as effective as possible, keywords should be designed to mimic a customer's natural language and thought processes, as opposed to adhering to strict headings and categories. This includes everything from vague plot descriptions (e.g., "books about fishing") to describing the target market (e.g., "gifts for dad"). Keywords are designed to supplement your existing metadata, not replace it, and this additional information only makes a retailer's indexing system more accurate.

It's important to remember that every keyword is an opportunity to increase sales of your book, and the best keywords are the most efficient and pragmatic. Repeating information that's already in the metadata isn't helpful, but many publishers do this anyway, while many don't use keywords at all. According to a Nielsen study on the importance of keywords, the average sales rate for books with keywords is 34% higher than for books without. By including keywords in your metadata, you are giving yourself a tremendous leg up over your competitors.

How major online booksellers are using keywords

Google

First and foremost, it's important to discuss how Google processes descriptive data elements in comparison to other book retailers. Though Google is obviously not just an online book retailer, a lot of book buyers use the search engine to find and research the books they want before moving into the purchasing stage. Google does take keywords into consideration when surfacing search results, but you should keep in mind that Google's search engine is far more sophisticated than your average book retailer's search bar for two reasons:

Google uses complex algorithms that process way more variables than the average book retailer when compiling search results. It primarily uses long-form content to collect its information – such as book descriptions, author bios, reviews, and awards information – while a typical retailer's search function only looks at the metadata that publishers feed into it.
Google is more sophisticated because of the intent behind the results it provides. It wants to give users the most relevant information possible, while Amazon, for example, only wants to make a sale.

There are many search engine optimization tools out there, but the main way you can make sure your book is visible on Google is by having accurate, robust, and up-to-date metadata and a solid description of your title.

Amazon

Amazon differs from Google in that its search results are entirely based on the metadata provided by publishers, and this includes keywords. Amazon is currently the only retailer that accepts and employs keywords in its search results. It does not pull from long-form content such as book descriptions or customer reviews, only a book's descriptive data elements. From Amazon's seller central, they tell retailers:

“Customers must be able to find your products before they can buy your products. Search is the primary way that customers use to locate products on Amazon.

Customers search by entering keywords, which are matched against the information (title, description etc.) you provide for a product.

Factors such as degree of text match, price, availability, selection, and sales history help determine where your product appears in a customer’s search results.

By providing relevant and complete information for your product, you can increase your product’s visibility and sales.”

Because people have such richer and nuanced experiences with books than with other products available on Amazon, keywords are more heavily relied on. Readers want to know exactly what they are getting into before making a purchase.

Previous Tech Forums have featured sessions from both Erica Leeman and Joshua Tallent on keyword implementation and how to optimize visibility on Amazon, with a specific focus on backlist titles. The videos of these sessions are available in full on our YouTube channel. They discuss the importance of making your book show up (and rank highly) in the most searches possible.

In order to do this, you need to have the best keywords, and these keywords have to be consumer friendly, not just marketing copy. It's important to understand your audience so that you can tailor your language towards them. It's impossible to predict exactly what people will type into the Amazon search bar, so having more than one keyword is, well, key. Having multiple keywords ensures that Amazon will combine them in ways that match what the user is looking for.

Joshua Tallent also mentions the importance of the "long-tail query," which is a more descriptive keyword that goes deeper than the top level. For example, your book may be a Romance novel, but more specifically, it's a historical romance set in Florence. By including keywords that use these more descriptive terms, you ensure that your book appears at the top of a specified search results list, as opposed to buried in the results of a more generalized search. Furthermore, long-tail queries show "high commercial intent," meaning that customers who are searching more specifically know what they are looking for and are therefore more likely to make a purchase.

Amazon's keyword limits aren't known, so it's best to create as many keywords as possible and put the most vital terms at the beginning of the list. Amazon also combines your keywords so it's not necessary to repeat any words. Keep it as clean and concise as humanly possible, and use words that consumers are likely to use. Including different versions of the same word is sometimes helpful, as long as you keep your audience in mind. Erica Leeman uses "United States" as an example. In researching popular Google search terms, she found that people are more likely to search for "US" than "United States", so it makes more sense to prioritize the acronym. The more frequently your book appears in search results, the more clicks it will receive. Clicks lead to sales, and sales lead to a higher search ranking and possibly a highly coveted spot on Amazon's list of recommended products.

Indigo, Kobo, and Apple

Neither Indigo, Kobo, nor Apple use keywords yet; they only use the basic metadata provided by publishers. That means your metadata needs to be top notch. It should not only be complete but also accurate to enhance discoverability. Just because these retailers don't use keywords doesn't mean you shouldn't be using them. Just thinking about keywords can improve your overall metadata because it prompts you to think more pragmatically about online searchability and the consumer's needs.

Online retailers (besides Amazon) primarily base their indexing algorithms on the following metadata fields: title, author, subject codes, and, in some cases, the book description. Some retailer algorithms take only the main subject words from the description, while others make the whole description searchable. In either case, it helps to have a well-thought-out and customer-oriented description that thoroughly outlines the book's themes, subjects, setting, and main character(s).

Further resources

There are a number of resources you can use to help you select good keywords, some of which are mentioned in Joshua Tallent's and Erica Leeman's Tech Forum presentations, as well as in the BISG's Revised Best Practices for Keywords in Metadata. These include search engine optimization tools, OCR scanners, and, most importantly, reader reviews. Knowing the words your readers are using to describe your book can be immensely helpful in narrowing down your list of keywords. Readers, as always, are the publishing industry's most valuable resource.

And if you are interested in seeing what keywords are already being used on specific titles, download our Chrome extension Biblio-o-matic, which automatically detects ISBNs in webpage content and quickly brings up the bibliographic information (including keywords) on any ISBN from BNC BiblioShare.