Why see the movie before reading the book?

There are lots of movies out now that were actually books first -  Frankenstein, The Running Man, and Hamnet is coming soon. So we're asking the question – do you have to read the book before you watch the movie?  Bookstore co-owner Jo Saul, culture writer CT Jones and film critic Bilge Eibiri join Elamin to weigh in, and let’s just say, they have strong opinions.