Religion is indeed a freedom of choice and whatever some choose is their business. As far as books most likely are millions all over the world 🌎
Holy books will out sell the unholy books, if it isn't a dark novel it could be anything that is referring to Satan like in The Ninth Gate or some call The Book of Shadows.
No matter what Holy will always out sell Unholy. My next post will be my opinions about The Ninth Gate.