liderul de opinie = opinion leadership

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Note added at 9 Min. (2009-03-28 13:08:42 GMT)
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References:
Wikipedia:
http://en.wikipedia.org/wiki/Opinion_leadership
"Opinion leadership is a concept that arose out of the theory of two-step flow of communication propounded by Paul Lazarsfeld and Elihu Katz. This theory is one of several models that try to explain the diffusion of innovations, ideas, or commercial products.

The opinion leader is the agent who is an active media user and who interprets the meaning of media messages or content for lower-end media users. Typically the opinion leader is held in high esteem by those that accept his or her opinions. Opinion leadership tends to be subject specific, that is, a person that is an opinion leader in one field may be a follower in another field. An example of an opinion leader in the field of computer technology, might be a neighborhood computer service technician. The technician has access to far more information on this topic than the average consumer and has the requisite background to understand the information."


And - more importantly - a marketing glossary:
http://www.surveybounty.com/articles/marketing-glossary.html
"Opinion Leader - A person who's opinions particularly influence others in society. Examples include celebrities and politicians."



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Note added at 14 Min. (2009-03-28 13:13:56 GMT)
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Sorry, I need to correct:
liderul de opinie = opinion leader

Maybe 'opinion leadership' might also fit, depending on how you translate the rest.