As a Mastercard cardholder you can receive a special 12% saving on your booking. To enjoy this great offer, simply visit: www.expedia.com.au/mastercard and enter the first 6 digits of your Mastercard card number to receive your unique coupon code to use on your hotel booking.
Book by 31 December 2017, for stays until 30 June 2018.
Sample MasterCard IIN (Issuer Identification Number): 555005
After getting the coupon, probably close the site and remove cookies, then visit it through cashrewards. Not all hotel websites honour cashback when you use a coupon, but last time Expedia did for me, resulting in an extra 5.54% cashback on top of the 10% discount coupon I used.