I just received an email from Amazon touting the next book in a series by an author I follow. The interesting thing to me is that this book isn't out yet. This is a separate "Coming soon from an author you follow" email, and in fact Amazon has also shown this book to me in its other KU email, "Featured in Kindle Unlimited"--that I received yesterday. The book, which I had pre-ordered weeks ago, doesn't release until May 2.
So...I think Amazon is doing some very heavy lifting indeed for this author, who writes in a rather unusual subgenre, the genuinely "clean" humorous Regency romance.
Actually, the bots can't tell time.
Anything new on pre-order gets tagged as 'New Release', even when the pre-order date is months away.
All the bot does is pick up the new release tag, and send that out as if it had been released already.
I get plenty of emails for authors I DON'T follow, and very few for those I do.
And they still send me emails for Romance books, and I've never bought one in my life.