Discounter Costco Wholesale appears to have finally achieved critical mass, six years after entering Australia, reporting a strong rebound in profit in 2015 as sales soared past $1 billion. 
Accounts lodged with the corporate regulator last week showed Costco Wholesale earned a pre-tax profit of $22.7 million in the 12 months ending   August 2015, compared with a pre-tax loss of $10.7 million in 2014, when the company invested heavily in new stores, and a $4 million profit in 2013.
Revenue jumped 50 per cent in 2015, from $878.5 million to $1.323 billion, as sales grew at existing stores and the discounter opened two new stores, taking its network of warehouse-style stores to eight.
Costco opened its first store in Adelaide in   November 2014 and its third store in Melbourne, at Moorabin, in   November 2015.
In 2016 Costco plans to open its third Sydney store, at Marsden Park, its second in Brisbane and its fourth in Melbourne, at Epping. It has also opened four petrol stations, in Crossroads (NSW), North Lakes (Queensland), Canberra, and Adelaide (Kilburn).
Sales have more than doubled over the past two years, from $612 million in 2013 to $1.3 billion in 2015, outpacing growth at rival discounter Aldi and the big supermarket chains.
Costco's stores are three or four times the size of a typical supermarket - about 14,000 square metres - and sell fresh, frozen and packaged food and groceries, often in bulk, as well as a wide range of general merchandise.