Provided is a messaging system that includes: messaging units disposed in different locations within a commercial space, each including a light-emitting diode (LED); a messaging/modulation controller coupled to the LED and configured to turn the LED on and off so as to broadcast a digital message as a binary-encoded digital signal corresponding to on/off states of the LED; and a user interface, coupled to the messaging/modulation controller, that permits a user to create schedules that specify how and when specified messages are to be broadcast by such messaging units. Different ones of the messaging units are configured to broadcast different digital messages, including substantive content that is different from what is broadcast by other ones of the messaging units, in accordance with the schedules input through the user interface.