The document discusses opportunities for monetizing mobile apps through various methods like in-app purchases, advertising, and virtual currencies. It notes that users are getting harder to acquire and retain for free apps. The document promotes focusing on advertising, as advertisers have large budgets to market to mobile users. It provides examples of how brands can do engaging ads through video, games, and social interactions to drive real outcomes like fan acquisition or purchases. The conclusion is that mobility creates new opportunities to make advertising an entertaining part of the user experience.