Readers of my blog will no doubt be aware of the importance of the categories and keywords your book uses. From using Amazon categories to increase your rankings to the perils of using keywords like Free, Bestseller, and Kindle, they can be used to optimize your book page. But, as I often say, book marketing is like building on quicksand: everything changes every other month.

No, it’s not that keywords are suddenly any less important — in fact, quite the contrary. It’s just that the way Amazon uses them to identify which books to display when a reader searches for a book to read seems to have changed lately.

Amazon Keywords, The Old Way…

As David Kudler of The Book Designer explains, it used to be that you could use natural-sounding phrases of two to five words for your keywords, especially those which returned between two hundred and a thousand titles on an Amazon search. If you did this, you had a high probability of being able to reach the first page of search results.

The “natural-sounding phrases of two to five words” bit was very important, since (particularly on Amazon’s KDP) the phrases you put in on the back end seemed to have to be either perfect or very close matches to the actual searches for your ebook to show up in results.

That is why David originally used the following keyphrases for his book, White Robes:

  • teen assassin,
  • strong female protagonist,
  • historical japanese women,
  • japan adventure,
  • female assassin fiction,
  • historical heroines,
  • seasons of the sword

And the New One

So, what has changed? Rather than using the KDP keywords as natural-language phrases, Amazon’s search engine now seems to simply look at all of the keywords entered.

To illustrate the difference, let’s see what David now uses as keywords:

  • teen assassin killer warrior swordmaiden kunoichi
  • historical japanese women girls lady action sword
  • female assassin fiction short stories quick reads
  • seasons of the sword series companion tales
  • strong female protagonist lead heroine girl woman
  • japan adventure true war story prequel risuko
  • historical heroines kickass broads babes fun

Yes, you guessed it: he now uses almost 50 words in here, not bothering with whether they’re making sense as a phrase or not. Essentially, he has taken these 7 fields and stuffed them with 49 keywords!

In David’s own words, “You’ll see that I kept the initial phrases intact — I’d spent some time trying to find them, after all! I then riffed on a number of words that seemed like likely searches that would lead a reader to White Robes — and make them likely to want to purchase it once they’d found it.”

Does it Work?

Here is Amazon’s ranking for White Robes, taken from David’s Author Central pages. He implemented the change on August 22 and did nothing else to boost the title’s sales (we can safely discard the downward slope on August 27, as that’s when he took the screenshot):

David Kudler's White Robes | From the blog of Nicholas C. Rossis, author of science fiction, the Pearseus epic fantasy series and children's book

Image: David Kudler,

So What? Big Deal

Well, actually it is a big deal. Clearly, Amazon now uses individual words rather than whole phrases. This has two major consequences:

  1. First, it’s no longer necessary to limit yourself to phrases that a potential reader is actually likely to enter. Even if natural phrases are still given greater weight, each keyword field can take up to 50 letters (including spaces). So, it suddenly becomes much more advantageous to add as many relevant words as you can. By increasing the number of words you’ve entered, you’ve literally made your target larger — and easier to hit. In short, you’ve increased your discoverability, which is the name of the game in book marketing!
  2. Second, since Amazon searches for the occurrence of a word in any keyword field, it makes no sense to repeat any words. Having said that, since David assumes that natural phrases are still going to show up as more relevant, he suggests prioritizing the most likely ones and keeping them together when possible.

Additionally, David had run a quick BookBub ad for the same title on July 27. You will notice that the Ad’s effect was slowly wearing off, leading to the slow downward trend in the rankings from July 28 to August 22. Note that by increasing the number of keywords, he managed a greater impact than a paid ad, at no cost.


David also reminds us of a few caveats, putting things in perspective:

  • The first places Amazon will look for a match to a customer’s search are the title and subtitle, the author’s name, and the description — and only then will it check the keywords. So, you still need to optimize your book’s page on Amazon: don’t forget the importance of a well-placed subtitle.
  • Avoid keyword stuffing — that is, just randomly dumping in words you’d like to show up in searches for. However, it is a good idea to include relevant words in ALL of your metadata, not just the keywords. David often has a parenthetical line at the bottom of the title’s description that includes highly relevant genre/sub-genre/style keywords.
  • Stick to truly relevant words: it does no good for your book to show up in a search if it’s not actually a book someone doing that search would want to buy.
  • Since Amazon seems to check for misspellings and (to a certain extent) variations, don’t worry about that: for example, there’s no need to put prequel, pre-quel, and prequel as separate entries.

Next on My To-Do List:

I’ll be trying out David’s approach for all of my books. Specifically, the following 3-step process he suggests:

  1. Use the whole of each keyword field (all 50 characters)
  2. Continue to experiment, seeing which kinds of keywords increase or decrease your discoverability (as reflected in your sales)
  3. Repeat

You can read the entire post on

[tweetthis]KDP Keywords Revisited[/tweetthis]