How do you measure the success of a mobile app? At one time counting downloads was a sufficient way to evaluate the success of an app, but that's no longer the case. Today venture capitalists and mobile developers are focusing on customer engagement, or interaction. Companies can use engagement metrics to see, in very granular detail, how customers are using products and this can produce valuable information, such as the market value of an app. What are the proper metrics to look at though to measure customer engagement? Find out in this FierceDeveloper special report.