In many such cases, a cursory search for causes finds that some small group of people was wearing, promoting, or developing whatever it is before anyone else paid attention.

　　【长难句分析图解】

　　篇章超精读

　　①The 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.

　　②Marketers have embraced the two-step flow because it suggests that if they can just find and influence the influentials, those selected people will do most of the work for them.

　　③The theory also seems to explain the sudden and unexpected popularity of certain looks, brands, or neighborhoods.

　　④In many such cases, a cursory search for causes finds that some small group of people was wearing, promoting, or developing whatever it is before anyone else paid attention.

　　⑤Anecdotal evidence of this kind fits nicely with the idea that only certain special people can drive trends.

　　参考译文

　　①“影响力人士”这种被假定的重要性源于一种听起来很有说服力但基本上未经检验的理论——“两步传播”理论，即信息由媒体传播给他们，再经由他们传播给其他人。

　　②市场销售人员们信奉这种理论，因为它表明，他们只要找到这些有影响力的人，并影响他们，那么这些被选中的“影响力人士”就能帮他们完成剩下的大部分工作。

　　③“两步传播”理论似乎可以解释为什么有些书籍、品牌或者社区突然会出人意料的火爆起来。

　　④在诸多此类情形中,粗略调查其原因会发现,有一小部分人在其他所有人留意之前,就率先穿戴、推广或开发这些东西。

　　⑤这些轶事证据十分符合这种思潮：只有某些特别的人能引领潮流。