Abstract: According to one aspect, embodiments of the invention provide a reactive display system comprising a display channel, data storage coupled to the display and configured to store pre-determined and reactive messages, a sensor configured to monitor at least one variable of an area within which the system is located, and a controller coupled to the sensor, data storage and the display, wherein the controller is configured to operate data storage and the display channel to display at least one pre-determined message in a first mode of operation, and wherein the controller is further configured to operate data storage and the display channel to display at least one reactive message in a second mode of operation in response to an indication from the sensor that the at least one variable has changed.