No, it's four hours a week that broadcasters.... So it's more like 3% or 1%, or whatever it comes out to be.
No, you don't have to subscribe specifically to it, but you do have to know how to activate the video description service, which in itself can be an obstacle. Look at your digital box and your remote control. Obviously, all of that is menu-driven, and there is no voice output for it. To be able to select the video description track can be a challenge in itself.