'Average use' is 50 GB/month, but note that it went up -5 gigs- in one year, and that that's an -average- across all fixed type lines. I.e., you are averaging people on satellite, grandmothers who just check email and facebook, etc, with the more typical family of four streaming video across multiple devices.

I want to know the distribution curve, because I bet it's a pretty flat distribution. Presumably Comcast knows that too, and that's why they even -have- that "use only 5 gigs a month and save $5", which is the biggest ripoff I've ever heard of, but which, for grandma checking her email, might make sense (provided her grandchildren never visit her and use the internet).