I just saw this in my email today.
Save 10% off your booking with Hotels.com and PayPal. Book by June 30, 2015. Travel by August 31, 2015. Use code: AUPAY10.
Credit to @4luk
Additional discount of up to 6% from Cashrewards (http://www.cashrewards.com.au/hotels-com)
Payment in part or full to the hotel at the time of the stay: 1.00%
Fully pre-paid at the time of booking: 6.00%
i find that agoda is cheaper even with the 10% discount. check around before going through these guys