The phone took only a few hours to switch from 'Available now'  to 'Available in one to two weeks' on Apple's website after pre-orders opened. It is the fastest-selling Apple product in history - outpacing both models of iPad, the original iPhone and every Mac in history.

In the UK, O2 was the first network to carry iPhone, it also has the largest number of people who will be nearing the end of their contract and therefore ready to upgrade,' says Dominic Sunnebo of analysts Kantar Worldpanel.Apple were keen to trumpet their results, after many tech websites and reviewers were lukewarm about the new gadget - pointing to the fact its specifications bring it in line with rivals such as Samsung's Galaxy S II, rather than pushing it into the lead. 

Apple observers knew that Apple's iPhone 4S had been a hit, despite a distinct lack of excitement from the tech community.