A passive audience is an audience that will initially pay attention to a message only because it is entertaining and offers a diversion. This type of audience is made aware of something through a brief encounter such as a billboard, poster, flyer, etc.
Communication channels ideal for reaching a passive audience are ones that can be accessed while doing something else. (example: driving a car and seeing a billboard). Messages targeted towards a passive audience need to be creative and stylish: something that will capture one’s attention.
Most PR campaigns are designed to reach a passive audience.