From reading some of these posts it is apparent that a lot of...

From reading some of these posts it is apparent that a lot of people have no idea the impact Costco is going to have in Australia. I have witnessed the effect on retail and wholesale stores in the UK. It is a phenomenally successful business that just prints money at the expense of other supermarkets in a wide geographical area around the store.
People will go out of their way to drive to Costco. The quality of the merchandise is very good (they only deal with suppliers that offer quality so they can back it up with their own excellent guarantee).
I expect that initially shoppers may not flock to the shop just as with Aldi, but look at Aldi now. Unlike Aldi, Costco only stocks branded products in bulk and you will see consumers recognise the value of shopping here where they can buy the brands they love and still make savings. Consumers may not use Costco for everyday shopping as they would Coles and Woolies, but they will stock up when they visit Costco and this will severely impact Coles and Woolies sales.
Another interesting fact...Costco had such a devastating effect on Walmart in the US that Walmart decided to open up a chain of stores called Sam´s Club which works on an almost identical formula as Costco.
I have been waiting for this company to arrive in Australia for some time. It is about time that Australian consumers are given a fairer choice of where to shop.
For those who hold shares in Woolies & Coles I would suggest adding some Costco stock (if you can) - this company is global and looking to move into other countries for market share (I don't see Woolies or Coles doing this).