Which type of appeal depicts a sense of community or social proof to promote participation?

The appeal that depicts a sense of community or social proof to promote participation is the "Join the Bandwagon Appeal." This type of appeal suggests that because others are participating or endorsing something, it is wise or desirable for an individual to do the same. It taps into the human tendency to conform to group behavior, implying that joining in is the popular or socially accepted action. This appeal effectively leverages the idea that if many people are doing something, there is inherent validity in that action, which encourages others to join for the sake of belonging or being part of a collective identity.

For instance, a marketing campaign that highlights the overwhelming number of users or supporters of a certain product exemplifies this appeal by suggesting that being part of such a large group can be advantageous or fulfilling.