From website:
Purchase a $500 Crown gift card online and receive $50 additional value.
T&C: Offer is strictly limited and valid for purchases made from 15 November -24 December 2018. Offer is subject to availability at time of purchase, one gift card is issued per transaction. Offer is valid with the purchase of a $500 gift card denomination. Offer is strictly limited and only available via Crown Gifts online. Offer cannot be used in conjunction with any other offer via Crown Melbourne, Crown Perth or Crown Gifts. Please refer to crowngifts.com.au for further terms and conditions on purchases via Crown Gifts.
Free delivery too, by the looks of it.
Offer keeps getting worse. Was Spend 500, get 100 extra last couple of week.