A group is defined as two or more individuals who share norms, values or beliefs and influence each other's behavior. A reference group is a group whose perspectives or values influence an individual's behavior, either directly through primary groups like family, or indirectly through secondary groups like clubs. Reference groups can be aspirational groups people want to emulate or non-aspirational groups people do not want to emulate. Friendship, work, shopping, and virtual groups can all serve as reference groups. Factors like an individual's information and experience, and the credibility of the reference group impact the degree of influence. Word of mouth and opinion leaders are important in spreading information between groups. Marketers leverage word of mouth and opinion leaders through various online