"we're really building a system to efficiently share opinions and see what other people think."
This is exactly it - well said. And as you said, "movies are your beachhead".
All you need is why what you do is different and/or better (which is still not exactly clear, unless it's finding peers).
It's sometimes tough for engineers to be focused less on being precise in description, and more inspirational to goals. I have to work at it every day.