At the Comic Con panel out of the 10 actors there, a Director, and a Producer (some random lady I've never heard of) ONLY Gwendoline Christie had read the books... like really? If I'm getting paid a ton of money to be on something like that... I'd be very motivated to read the source material.
Most Helpful Girl
They might do that on purpose to avoid building up unreasonable or faulty expectations about how the movie should be.0
Most Helpful Guy
It's a long freakin' book.1