A customer service machine, such as a self check-out terminal, includes a visual indicator and a proximity sensor associated with certain functional components or stations of the terminal, such as itemization, bagging and payment stations. The visual indicator is configured to provide a visual signal to either encourage or deter customer activity at the particular station, depending upon whether any activity is required to further a transaction being conducted at the terminal. The proximity sensor at each station determines whether the customer is about to take action at that station. A controller determines whether the action is appropriate, and if not activates the visual indicator to deter such action, or if so activates the visual indicator to encourage such action. In one embodiment, the visual indicator includes a red light that is illuminated to deter action and a green light that is activated to encourage action.