I never considered earth to be particularly conductive. It's just dirt, after all.
However, I've seen "earth ground" conductive stakes driven into the ground in order for electricity to be grounded, because it will find its way down there.
However, it never made sense to me why earth would even provide such an effect: why electricity would bother to flow to dirt out of all the conductive goodness inside the circuit?
What characteristics of earth/electricity makes the current flow right into the ground?