Mobile used to be cheap. It isn't anymore. The days of driving impressive returns from a mobile-optimized website or app that replicates the functionality of your website are long gone. Moreover, the cost of app development is a drop in the bucket compared with the cost of powering apps through infrastructure that taps into real-time information and services. Understand the business case for mobile before you embark on the journey. This report lays out the process and coaches digital business pros through estimating the benefits, total costs, and risks of mobile. This is an update of a previously published report; Forrester reviews and updates it periodically for continued relevance and accuracy.