Appears to be a recurring deal based on previous OzBargain history.
The fine print provided by Groupon is somewhat confusing, as the top of the document states, in no uncertain terms, that the voucher (the code) must be used by January 31st 2017, however in the body of the text it says February 7th. There is also a confusing reference to travel commencing from November 27th 2016, though I suspect that is related to the previous promotion, which ended on the same date.
Their prices seem reasonable, I have used them before, and 20% off makes it even more competitive. As it's a voucher provided by Groupon, unfortunately you can't stack the current 13% off promotion.
Enjoy.
How are these guys? Reliable?