The mobile applications business is a growing one although the question of how lucrative it is is still up in the air. The research firm sees a jump from the current $10 billion in revenue generated by app stores, markets,worlds, etc. to a forecast total of $32 billion in revenue by 2015. Apple's App Store has had 4 billion apps downloaded since its start, resulting in $1.5 billion in sales. For Juniper's forecast to be correct, other platforms offering apps-like the Android Market, BlackBerry's App World and the Windows Marketplace for Mobile will have to get the whips crackling, especially when you realize that Juniper estimates that only 15% of apps must be paid for. An increase in download volume, thus does not necessarily lead to an increase in revenue. The author of the report noted that concentrating on smartphones to offer third party apps is a mistake and if the industry wants to introduce a model based on applications, it needs to offer apps to non smartphone (featurephone) users.