Look, I know that my challenge question asks for a book recommendation, which isn't exactly a high bar. If that recommendation is for your own book, I am not going to accept your request, and I not going to read your book.
If you use the recommend feature to recommend your own book to me, I am not going to read your book.
If you comment on one of my reviews to recommend your own book, I am not going to read your book.
You are not an exception to this rule, random stranger.