It's definitely keyboard, not mostly mouse. I think APM of 300 is more normal, but peaks of 500 happen. But APM includes things like "spamming" hotkeys, where you hotkey your buildings to say keys 4, 5, 6 and flick through them to check whether they're done building/training, and clicking like crazy before a unit can train yet (to make sure it starts ASAP). Example of Flash playing SC2.
There's another thing called EPM, which is Effective actions Per Minute. That eliminates most of the spammy kind of things (there's also where you right-click spam with the mouse on the ground many times to order a unit to go to basically one place but you're sort of perfecting the position, for example).
Perhaps the powerplant could charge for it.
I see what you did there.
//GO.SYSIN DD *, DOODAH, DOODAH