The firm, which provides fashionable twenty and thirty-somethings in 160 different countries with copies of their idols' wardrobes, despatched two million orders in December while sales rose to just under £80 million.
ASOS, which stands for As Seen On Screen, said the rush for onesies, the all-in-one adult pyjamas worn by everyone from Cheryl Cole to Nick Clegg, helped sales rise by a bigger-than-expected 34% in the UK.
Trends such as bold jewellery, as worn by Beyonce, and baroque, the lavish, gold-embroidered trend seen on catwalks last autumn, were also big sellers. Chief executive Nick Robertson said cutting prices to match budget brands such as Primark played a role. He added: "Our customer isn't any wealthier than a year ago so adjusting our prices was key."
ASOS also hailed social media initiatives such as "shoppable films", where viewers can purchase items while watching promotional videos.
Mr Robertson said: "Social media is an important factor for us – not just promoting and connecting but making it easier for the customer."
The rise in customers should spark a rise in jobs. The company currently employs 1500 staff at its Barnsley warehouse.