Well, I'm not exactly sure if I'm what you call a "movie member." I read the books before I saw the movie, but I read the book because of the movie.
I don't think being a movie member is a bad thing. I'm glad to see the movie has sparked so many interests for LOTR and other works by Tolkien. I was surprised to see so many students in my school I'd consider as non-readers carrying around LOTR and The Hobbit to their classes after the first movie came out.
A movie member can also be a real true Tolkien fan. Here is how I believe a movie member may sometimes grow:
A fan of the movie will wander over to the Barrow-Downs out of curiousity and register. After reading several threads in forums like Novices and Newcomers, the new member will become interested enough about LOTR and Tolkien to read the books. If that member enjoys the books as much as they enjoyed the movie, their love for Tolkien and fantasy will grow and they will become inspired enough to become involved in RPGs and in-depth discussions. And there you go: a new Tolkien fan has just been born.
I don't mind members here who haven't read the books. In fact, I admire them in a way. I don't think I could've lasted at the BD a week if I had not read LOTR or The Hobbit before registering.