What is the relationship between credibility and persuasive communication? What is a way that credibility can be undermined? How does this relate to a communicator's self-interest?

What will be an ideal response?

Communicators who are credible—who seem to know what they are talking about or who are expert with respect to the topics or issues they are presenting—are more persuasive than those who are seen as lacking expertise. Communicators can, though, lose their credibility and therefore their ability to persuade. One means by which credibility can be undermined is if you learn that a communicator has a personal stake (financial or otherwise) in persuading you
to adopt a particular position. Because of this, communicators are seen as most credible and persuasive when they are perceived as arguing against their self-interests.