Answer:
Because of informational social influence.
Step-by-step explanation:
The message worked better than telling people other reasons why they should conserve energy because of informational social influence. Social influence refers to how people change their thoughts, or behavior to conform to the others and to be liked by them. People pay close attention to the behavior of others and imitate it. Recent studies showed that direct observation of others is not necessary if you communicate the norm as it was done in this case. People will change their behavior and they will start conserving energy as their neighbors do.