/r/ harrypotter did this and the increase in the quality of the content was absolutely fantastic. It went from overused memes and pictures of marginally related items to some actually quite fascinating discussions. I loved these books, and I enjoyed the movie, and when I came to this subreddit I had significantly higher hopes for the content here, but unfortunately it has fallen short. As a result, I think it would be a quite beneficial challenge to go text submissions only for one week, maybe more, and see if the content quality improves.
EDIT: My contribution to the revolution
EDIT 2: My next contribution