$50 for $100 to Spend at Intrepid My Adventure Store

You can use it to purchase domestic flight, although there is an extra $15 surcharge. The effective discount is $35 off the domestic flight ($50 extra credit minus $15 surcharge).

Honestly speaking, it is not the best deal I ever see. If you plan to buy any domestic flight within 12 months, it is worth to give it a try.

Store location: http://www.myadventurestore.com/contact-us/stores/

Fine Print
•1 voucher per person
•Buy 3 additional as gifts
•Limit of 4 vouchers purchased per customer
•No refunds for change of mind
•Card expires 12 months from date of issue
•Intrepid My Adventure Store not obliged to accept use of card for sales under $20
•Redeemable in-store at participating Intrepid My Adventure stores within Australia

Terms: http://www.groupon.com.au/universal-fine-print