Keywords are used by the book metadata in many ways. They are listed by themselves at the file upload. Not only that, they can also appear in the title and subtitle, book descriptions, and the author bio. Keywords in a book’s description help online search engines connect people to what they’re looking for. If specific enough, eventually your book can show up in the search results. Keywords also help people to make discoveries of products they didn’t know existed. Like your book. It is suggested that you save the best, most descriptive keywords to put in your title and subtitle.
As mentioned earlier, book distributors give authors space to add keywords during the title upload. It takes some experimenting to find a winning combination of keywords and phrases. So you must watch the results and make changes to the keywords from time to time. KDP gives space for 7 keywords, while IngramSpark gives space for 10 to 20 depending on the number of characters in them. Some recommend ordering them by importance- placing the best keywords at the top of your list. You can find your book’s best keywords and phrases using the Publisher Rocket app. It dose have a one time fee to setup an account. However, I have not used their service as of yet. But a few indie authors, online, say it works. But, there are a couple of free ways to do this. One way is to use Google Ad Words to find keywords through a Google Ads account. And another is to just go to the Amazon website and in the search bar type your book title, subtitle, and related terms from your book description one at a time. Notice as you begin to type letters, peoples’ most searched terms appear. The terms populate in a drop down list as suggestions for your search. Do write down all the related words and phrases. Separate each of the keywords with semi colons. Then, repeat those steps using new words to get more keywords. Use the space provided to continue building your keywords list on page 17