The figures reflect the massive interest in advertising for the third screen – or fourth, depending on how you count them. Indeed, Strategy Analytics predicts mobile advertising will account for a fifth of global spending on Internet advertising by 2011.

In recent weeks, the sector has been the subject of much M&A activity with the acquisition of Third Screen Media by AOL and ScreenTonic by Microsoft.

Phil Taylor, director of global wireless practice, said: “The supply of advertising inventory is rapidly increasing as mobile publishers look to develop advertising as a revenue stream. Major mobile network operators like SprintNextel, Verizon Wireless and Vodafone have all accelerated plans to sell advertising within their mobile media channels and advertisers appear to be responding positively."