Amazon Australia country manager Janet Menzies says the e-commerce giant has reached a milestone, offering consumers more than 200 million products, which will be a big advantage as rivals Wesfarmers and Woolworths look to beef up their online marketplace offers.

The battle for online dominance is in full flight after Woolworths in May offered to buy an 80 per cent stake in MyDeal.com and Wesfarmers entered the space after buying Catch.com about three years ago.