Richard Edelman is championing the need for PR agencies to completely change the way they work and has some sharp words for corporate marketers, most of whom are still focused on controlling the message. “You cannot control the message. You have to accept that fact.” He cites the GM chevyapprentice.com campaign as an example of how a company took a chance, got some flack, admitted there were some negative results and moved on.

He says corporations that don’t accept the need for a conversation-based approach to the business are burying their heads on the sand. “Only 30 of the Fortune 500 companies are blogging. That’s pathetic.”

“You cannot just have a top-down conversation where you buy a certian number of impressions,” he said of conventional marketing wisdom. “It’s a horizontal conversation. It’s top down, peer-to-peer and an open discussion.”

Conversation-based marketing is scaring advertisers “The ad guys are terrified. This is ruining their revenue model.” He’s clearly positioning PR agencies as being competitive with advertising agencies in social media and having a chance of stealing away some ad business.