HW#8 - Need Advice Re: Onboarding Sequence - Book Reviews

I’m finishing up my 5 emails for the onboarding sequence for my newsletter. For email #3, the book reviews, is best practice to keep the number of reviews under 3 books, like the example in the Newsletter Onboarding Sequence .doc? I’d like to give a few examples of both old and new books, but don’t want to turn off the reader with too many. I’d keep each review brief, like the examples of Heinlan’s book reviews in the example doc. Any suggestions re: number of books for the Reviews email, much appreciated!