Let’s take a step back. What does OP hope to gain by having am intro from a famous person in this corner of the industry? Is the premise that “Someone will see I was endorsed by Name so they will be more likely to buy the book?” That might be a reasonable expectation if you think people will physically pick up a book before purchasing it, e.g. at a bookstore. Is that what you think will happen… or are sales apt to be primarily online? …In which case, I’m not sure you need to bothe...