For some reason my account showed this code even though I had already used my free 30 day trial- I'm guessing it is replacing the $20 off coupon found here https://www.ozbargain.com.au/node/536077
So basically limiting you to what you can buy compared to the $20 off deal, although the plus side is you get an extra $10 to spend. Should work for any new sign up using a different credit card.
Some items for free-
From the comments it now looks like they aren't offering a free gift with the trial anymore, looks like they want you to sign up for $49 to get the gift now- marked expired