Surprised no-one has highlighted this yet.
Basically, spend $50 or more in iTunes giftcards (can be a mix of denominations or a single $50) and get a free $10 Coles Group and Myer giftcard. Limit of ONE $10 giftcard per transaction! This means if you're loading up on giftcards, it's best to pay in $50 increments to maximise the use of this offer.
Not a bad alternative to the usual 20% off deals that happens every fortnight or so.
And pants.
It's a good deal but FYI iTunes card are 20% off permanently at OfficeWorks