Marketers have embraced the two-step flow because it suggests that if they can just find and influence the influentials, those select people will do most of the work for them.
2010年考研真題（英語(yǔ)一）閱讀理解 Section Ⅱ
The supposed importance of influentials derives from a plausible-sounding but largely untested theory called the"two-step flow of communication": Information flows from the media to the influentials and from them to everyone else.