The concept of Tjoos is quite neat — aggregating coupons by store, and verifying that they work — but in practice the site is still a bit too rough around the edges. Although Tjoos is based in Australia, the operation is heavily biased towards US vendors, and there’s no efficient way of just searching for coupons in a given country (other than a handful of tags for capital cities).
Adding ‘Australia’ to search terms doesn’t help; your best bet is to pick a store, search for it by name, and scan the results to see if the Australian operation is present. The verification also seems a tad spotty: when I tested two of the more obvious candidates for coupons in Australia (Dell and Dominos), neither had any verified coupons present. (Tjoos estimates that about 10% of the coupons listed on the site had been tested to establish they work.)
With more work, Tjoos could be useful, but right now you’re better off sticking with local operations like OzBargain or Retailfans. Wherever you source your discount codes, check our guide to getting the most from those bargains.