Abstract: Methods, apparatus, systems, and computer-readable media are set forth for providing digital and non-digital content to a segment of a population that is identified using geolocation data and other activity data. In some implementations, non-digital content is delivered via postal mail to a segment of a population according to whether the segment of the population viewed certain content before, during, or after visiting a particular geographic location. In other implementations, digital content, such as phone calls or voice messages, can be delivered to a segment of a population according whether the segment of the population is present or has recently been present at a particular location and previously viewed certain content associated with the location. Segmenting populations in this way can conserve computational resources and materials that might otherwise be wasted on serving a larger population that may have less of an interest in the content.

Abstract: An infrared video camera system having a plurality of interchangeable imaging lens units and optical filter units. Identifying information, used to modify the operation of the camera system based on the specific imaging lens unit and optical filter unit attached thereto, is stored in an Electrically Programmable Read Only Memory (EPROM) located in each imaging lens unit and optical filter unit.