The Jetabroad offer has now been posted by someone on OzBargain, which has an active and fast-moving readdership.

If you've not tried to use this yet, you should either try now or monitor the link here, where you might get comments once the cashback's exhausted. I'd expect the cashback to be exhaausted VERY soon!

Note the linked info here mentions ALL international bookings; check that for yourself:
http://www.ozbargain.com.au/node/18447