Every book you read earns you points and rewards.
My wife found this and has started her qualifying statistics. She has not even come remotely close to entering all the books she has read and is already a Grandmaster. Which means something, somehow, when the game starts. One gets points for reading about detectives, family life, historical settings, military campaigns - all kinds of stuff. I think part of the purpose is to encourage children to read - which is why a librarian with 35 years' experience has such an advantage in Game of Books.
I cynically observed that the people playing would be those children who were already going to read lots of books, so no value-added there. But upon further review, boys do pay more attention once you start keeping score, and checking out ways to level up in multiple categories with one book is right up their alley. It might work.