Backend keywords

KDP gives you seven keyword boxes, and each one holds a phrase rather than a single word. They feed Amazon's search index, so their job is to cover the phrasings a reader might type that your title and description do not already contain.

The common mistakes are all forms of waste. Repeating words already in your title and subtitle adds nothing, because those are indexed anyway. Nor do the boxes need commas or quotation marks — a box is one phrase, and punctuation inside it is treated as part of the text.

KDP's own guidelines prohibit several categories outright: other authors' names, trademarked terms you have no right to, claims about sales rank or quality, references to Amazon programs, and time-sensitive statements. Those rules are enforced, and a book can be suppressed for breaking them.