If that is truly all-in (including exchange fees) then that is very interesting.
CME exchange fees were given last week. I don't have the link handy. They are like .20c, (but dependent on membership type/group). AMPs .40c all-in per side is double, and includes applicable routing fees. It is all-in cost PER SIDE. Again, based on MY setup, YMMV.
The biz model is clearly a small number multiplied by a larger number is a larger number!