In this episode, Aubrey and Justin discuss geo-fencing - the use of location services to detect region boundary crossing events - to prompt user action. When this type of prompt is used effectively, it provides a subtle guide to help the user achieve a task they want/need to do without being intrusive. When abused, it leaves the user feeling annoyed and disappointed. Just as we form impressions of our machines, they cultivate an understanding of us during the conversation. Voice control illustrates this effect elegantly with its uncanny ability to understand our intent, despite our imperfect expression.