I'm a librarian who loves anime, manga, and reading a wide variety of genres.
I checked my work inbox and found an email that basically said, "Since your library already owns books by [author], you may also want to purchase [author's] new historical fiction novel. It has gotten uniformly enthusiastic reviews on Amazon!"
Yeah, that last bit means absolutely nothing, considering that all it takes is friends and family writing 5-star reviews for a book to have "uniformly enthusiastic" ones. Still, I did some searching. The books we own are the author's traditionally published nonfiction. The book the email is talking about is the author's first (?) foray into self-published fiction. We're not a public library, so I don't see this happening. Although now I'm curious as to whether every librarian in my library, and all libraries listed as owning books by this author, also got this email.