For ebooks, there’s a website that will mail daily specials, these are free or on sale ebooks. My favorite feature on their site is to follow favorite authors. They then email me when those authors have new releases or books at a lower cost; I have been on their mailing list for several years – they emailed me about the favorite authors feature. One thing I discovered is that if I go through their links to get free books, the number of book links they send me becomes smaller. My workaround is to see the listings in their emails and go directly to Amazon for them.
URLs here: https://www.bookbub.com/home/ https://www.bookbub.com/users/sign_in#authors-search