In an exemplary embodiment of this invention, a vending machine may include sensors for capturing audio and visual data. A processing unit in the vending machine may analyze this data to calculate an attention score that is indicative of whether attention is being paid to the vending machine. Alternatively, or in addition, the processing unit may analyze this data to calculate the gender or emotional state of a person. Based on these calculations, a vending machine may alter its behavior, such as by changing its audiovisual output.