On the Kobo website, you will see that below the information on your book, Kobo will also list "People That Read This, Also Enjoy". Similarly, on Amazon, the will list "People That Bought This, Also Bought".
In both of these cases, if you click on the details of the books listed on the same page as yours, pay attention to what categories that those books are listed in. The odds are that you will a pattern and if you are seeing that these books are listed in categories that you are not, that may be an indication that you need to re-evaluate the categories that your books are listed in!
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