How can developers get more consumers to spend money inside a mobile game? A few companies are working with developers to help make that happen. For instance, TapJoy's new nGen platform combines a variety of native ads and traditional formats like interstitials with an analytics tool that can measure user behavior and provide contextual ads at key moments in gameplay and target specific groups. Meanwhile, another way to tackle monetization is to make sure that if you spend money acquiring mobile users, they're going to be engaged from the start. That's the philosophy behind AppEngage, a rival ad network run by Mountain View, Calif.-based Midverse Studios and founded by former Tapjoy executives. For more on these trends, check out this FierceDeveloper special report.