A reference group is "an actual or imaginary individual or group conceived of [as] having significant relevance upon an individual's evaluations, aspirations, or behavior."6 Reference groups influence us in three ways: informational, utilitarian, and value-expressive. Table 11.1 describes these influences. In this chapter we’ll focus on how other people, whether fellow bikers, coworkers, friends, family, or simply casual acquaintances, influence our purchase decisions. We’ll consider how our group memberships shape our preferences because we want others to accept us or even because we mimic the actions of famous people we’ve never met. We’ll also explore why some people in particular affect our product preferences and how marketers find those people and enlist their support to persuade consumers to jump on the bandwagon.