Digital platform providers Amazon.com, Apple, Facebook, Google, and Microsoft are competing fiercely to find the next big method to grab more minutes of attention. One of the most important tools in their arsenal will be voice control and monitoring. Far more than just replacing keyed-in commands, a system of voice control and monitoring — what Forrester calls "vox" — will provide entirely new avenues through which to deliver value to consumers. In this report, we explain why voice matters so much and paint the picture in vivid colors with a hypothetical example that hasn't yet happened but likely will. Marketers and app developers will need to prepare for the arrival of this powerful new interface.