Considering that QF claim they have 7 million members, and that each member needs to travel a minimum of 4 segments per year, and keep in mind that the minimum earn is 1,000 per flight, you'd be looking at in the billions for that alone (28 billion points based on every member doing the minimum), without counting the fact that you really need 8,000 points to actually start doing anything.
Remember than an individual point is not really worth a lot. So 500 million might seem like a lot, in reality, given the average price of a point is 2c, it would mean that the whole scheme would only have a value of $10 million.
Edit: Strangly enough, if you devide 28 billion by 2c, you end up with $560 million. So they may have been talking dollars worth of the scheme.