I wonder what's the percentage of code that 37signals produces that goes into Rails itself, and how does it compare to their actual applications. I bet it's so

I wonder what's the percentage of code that 37signals produces that goes into Rails itself, and how does it compare to their actual applications. I bet it's something like 9 to 1. Don't get me wrong, I love Rails and thank you, 37signals, But let's not distort the reality: Rails is their biggest cash cow they are milking, and there is absolutely nothing wrong with it.