You don't have to earn all your revenue just on purchases of the application. It is also possible to sell virtual goods from within your (cheap or even free) a

You don't have to earn all your revenue just on purchases of the application. It is also possible to sell virtual goods from within your (cheap or even free) application: http://www.insidesocialgames.com/2009/11/30/ngmocos-free-to-play-iphone-games-hit-the-top-grossing-apps-list/ http://www.insidesocialgames.com/2009/11/30/ngmocos-free-to-...