John Cass has been musing about how to build credibility via WOM advertising and 3rd party advocates. He's got a few ideas on how to get this going. If anyone has more, please add them via comments on John's site.

* Associate your company with national or regional associations
* Find credible spokespeople
* Write case studies that tell compelling stories from real customers
* Get some good press from your industry's media
* Understand your company’s strengths and larger connections, communicate the strengths and connections consistently

These are pretty fundamental, but that still doesn't mean that everyone is doing them.