The appstore model pioneered by Apple will unquestionably become the predominant model for mobile phone users, with remarkable growth prospects in the next few years. Mobile application downloads will exceed 4.5 billion this year, growing to 21.6 billion downloads by 2013. Consumers will spend US$6.2 billion this year in mobile application stores, growing to US$29 billion three years from now. Free applications will continue to account for an ever greater share, growing from 82 per cent of all downloads in 2010, to 87 per cent of downloads by 2013. This year alone, advertising revenue is expected to generate US$600 million worldwide.