Abstract: A method includes receiving location data for a movable object, the location data specifying geographic locations of the movable object over time; defining dimensions of a virtual boundary in real-world physical space based on the geographic locations of the movable object over time and configuration parameters for the virtual boundary; sending data indicative of the virtual boundary in real-world physical space to trigger delivery of content to mobile computing devices within the virtual boundary; and actively adjusting the configuration parameters for the virtual boundary in response to a number of the mobile computing devices within a region while continuing to receive the location data for the movable object, define the dimensions of the virtual boundary, and send the virtual boundary to trigger delivery of content.