JR Duty Free has changed their regular 20/15% off at selected airports to a new offer of 50% off a 2nd full-priced item, when 2/4/6 etc items are purchased online at the same time. Discount is applied to the lower priced item(s).
Applies to alcohol, cosmetics, watches, travel goods etc (check the T&Cs for full list of included and excluded categories), for inward and outward purchases.
Brisbane, Canberra, Darwin and Perth Intn'l airports only.
Also includes the chance to win one of 2 BMW i8 worth ~$320,000ea, when you purchase liquor for $100 or more - but only in Brisbane or Perth. T&Cs apply - but interestingly, it appears you don't have to be a resident of Australia to enter.
This part deserves a separate post in the competitions I think.