The ‘freemium’ sales model – offering free basic services with chargeable additional services – will become increasingly common over the next few years, according to a report from Juniper Research. It says annual revenue from value-added services upsold through downloaded applications (i.e. not money made from selling the application but money generated by the application itself) is expected to exceed $14 billion by 2014. This could cause problems for network operators and even for some ‘app stores’ because payments could go directly to the application provider without the original store owner taking a percentage. [Press release; report]