The figure you're quoting was actually $3.29 billion as it includes all lottery activity.
If you want the actual figure - look
here. You'll see that Tatts only took in a profit of 123.6 million in 2011 for its racing and sports betting activities. Not that impressive when they have an online presence as well as "over 1200 retail and on-course outlets" according to them.
As you'll see from their balance sheet their revenue from that division was actually 593.5 million in 2011 (down a million from the year before despite bragging about their expanded fixed price service). $300 million was paid out in racing industry fees and government taxes. A figure that will now only increase. I guess not only does it suck to be an Aussie horse racing bettor now but a Tatts shareholder too.