Bhagwan, I am not sure if we Qld punters are more astute or more stupid.
As I understand it the Qld TAB does not pay a set % of the pool for a race as divvies, it pays what it reckons is a fair divvie.
How it arrives at that figure is anyone's guess, but the TAB is reported as saying they have to be competitive with other betting outlets.
(Info from Mon Courier, The Ear section)
It came as a complete surprise to me, so there really is a million ways to do your dough apparently.