I teach word of mouth marketing.
Why? Because companies that understand this stuff are more open, transparent, honest, and kind. Because companies that learn to get people talking (and learn to talk back) are better businesses. It's about one big idea: Companies that make people happy are more successful.
Your idea, cause, or business won't succeed just because it's great or worthy. It will succeed when you earn the respect and recommendation of a community that will carry your message for you.
I'm the author of "Word of Mouth Marketing: How Smart Companies Get People Talking." I run a site called WordofMouth.org , which teaches word of mouth techniques to marketers and entrepreneurs, and SocialMedia.org, a community for social media leaders at the world's greatest brands.
I'm also a rabid purist on the topic of marketing ethics and travel the country teaching companies how to stop being jerks to their customers.
In past lives I taught internet entrepreneurship at Wharton, taught word of mouth marketing at Northwestern, ran a business incubator, and started half a dozen companies. I like starting communities -- I created the Word of Mouth Marketing Association and, back in the dotcom days, I ran the Association for Interactive Marketing.
My blog is called "Damn, I Wish I'd Thought of That!" (www.damniwish.com).