It is a fair criticism, is it not? My go-to for this issue is my Kindle Paperwhite for which I did not spend the extra $20 to turn off the ads. Amazon has over ten years of my reading habits, which mainly consist of sci-fi, philosophical/religious non-fiction, and miscellaneous dregs. You know what I have never, ever read in my life? Some along the lines of the "Witches of Paragrene Point" series of books. Or the "Defending $POPULAR_90S_GIRL_NAME" series (which I take to be "manly hunk is bodyguard for a female has to rescue her at some point"). But those show up on my Kindle, at which point I assume Amazon just isn't even trying.

After about ten years or so of Kindle ownership, I recall clicking the ad and buying the book exactly once. Yup, a sci-fi book, and it was pretty damned good as I recall. The title, you ask? Hell if I know, Amazon never showed me another book from that author ever again. And I wish they would, because I can't remember which one in my "stacks" of sci-fi is the one I want.