The natural human tendency to be influenced, whether directly or indirectly, by other people's choices. People are much more likely to do something if we see someone we know has done that thing as well. This is called social proof and it motivates people to take action. Social group identity, participation, and recognition are powerfully rewarding to people.

Design Implication: Enabling social dynamics in your software can bring increased engagement, virality, community, reward, and growth.

Examples:

• user-generated reviews and comments (reviewers can be rated and participants can gain rewards for being a good reviewer)
• everything is a social object that people can virtually gather around (anything can be shared, rated, have a discussion thread attached to it, etc.)
• collaboration, whether virtual, live, or asynchronous
• help systems (an online support community is a valuable part of a complete help system)