Idea 2: Build “Appisodes”
Many games can utilize this idea to keep their customer’s engaged. If your app can benefit from new levels of play, or new themes, you will benefit from regular updates of your app. Pocket God, for example, has benefited handsomely over the past few years by providing new Appisodes of their popular game. They now offer new episodes through In App purchase capability, and they are always offering news ones to keep their customers engaged in using their app.
As people use your app on a continuous basis, the more likely they are to recommend it to their friends. Word of mouth is huge when selling apps, and you need as many people as you can to talk about your app.