The company, founded in 2007, has become an internet phenomenon and is now worth nearly $US7 billion.
With more than 7 million customers around the world, the retailer says it expects to make a bigger profit this financial year.
ASOS chief executive Nick Robertson says the company does little traditional advertising and sales have been boosted by their customers' recommendations on social media sites.
He says because ASOS is a unique proposition, it gets talked about.
Mr Robertson says the retailer is about to launch in China.