Keywords are one of the most effective ways publishers can promote Kindle eBooks on Amazon. And like any effective tool it attracts its fair share of misuse and abuse. As a consequence, Amazon enforces strict rules about their use and has been known to take swift action against books (“take downs”) when these rules are violated.
What are Amazon Keywords?
Each Kindle book listing on KDP can have a maximum seven keywords, separated by commas. The only other major eBook store that offers this book discovery tool is Barnes & Noble and their store allows a maximum of 100 characters. (I have never experienced a character limit for Amazon Kindle listing keywords.)
A keyword can be more than a single word; it can actually be a phrase like, for example, modern architecture or true crime. It’s also sometimes called a search term. But whatever you call it, it works the same across every search engine—enter a string of words and you get relevant results.
5 Best Practices for Choosing Keywords
- The number one rule for choosing keywords is don’t try to game the system. If you use the name of a competitive book, or a popular author, your eBook could get removed from the store, or worse. This also includes words that refer to sales rank (“best selling”) and marketing terms like “free” or “on sale.” Avoid referencing anything that is unrelated to your book’s content.
- Certain fiction sub-categories require publishers to include specific keywords so that the book will show up in that category. Romance, science fiction & fantasy and erotica are three examples. Learn more here at the bottom of the Selecting Browse Categories page.
- Do not repeat words already included in your title, subtitle or category and other key metadata fields. Yes, this runs counter to SEO best practices where some repetition can actually help your rankings. Perhaps Amazon doesn’t want us clogging up search results with irrelevant results, or perhaps it gives those that do repeat keywords an unfair advantage. One reason I can see not repeating title or sub title words in the keywords field is that you get only so many high-value opportunities. (Personally, I haven’t had a problem repeating words but I’m also not certain how much it helps.)
- Test your keyword ideas by typing them in the search box on Amazon.com. As you type you will see a list of words or phrases that match your entry. Write some of these down for use in your keyword field on KDP. Keep in mind that keywords can vary by product type and may be different between print books and Kindle eBooks.
- Don’t hesitate to change your keywords if you see an opportunity to ride a wave of interest in a trending keyword, as long as it is relevant. If you do change them, make sure they are consistent across other formats (eBook, print, audio).
Amazon's Kindle keyword field in KDP is one of the main reasons why I advocate distributing your eBook via KDP rather than through a third-party distributor. (See this video on aggregator vs. self distribution eBook distribution.)
Also see my article titled How to Choose Keywords to Sell Your eBook.