The marketing world is based on the notion of sellers trying to communicate to buyers. How do we know that the 17,000 year old cave paintings at Lascaux, France weren't really ads for the latest hunting tools? The goal is to convince buyers that they need (or better yet cannot live without) what you're selling. In some cases the need is real (food, water, shelter) and in others the need is artificial (furry toilet seat covers, Belgian waffle makers, Naive bottled water). The perferred method of communication is one-way messages.
But buyers have always had a harder time trying to communicate to sellers. No thanks to sellers (non-human corporations). Their stuff is real. But they are not. Anyone who's ever dealt with customer service knows it's an oxymoron. Technology has been the buyer's best friend when it comes to communicating to sellers...or better yet other buyers. Guttenberg's little invention gave fire to the masses, and it didn't take long for the conflagration to begin. Next stop, Consumer Reports. The Internet has done the same kind of thing.
Marketers spent centuries creating three enormous one-way streets for communication: Print, Radio, and Television. It was mass marketing to support mass industry. Then along came the Internet, and it blew the lid off everything. Joe/Jayne Smith didn't have their own magazine or radio program or television show...but they had the Internet...and they used it to go the "wrong way" down the one-way street. Email, Usenet, chat rooms, message boards, and Web sites gave local yocals global voices. Next stop, Google Groups.
And now for my point (albeit long winded). Ask anyone in marketing or advertising what the most valuable form of communication is and most will tell you word-of-mouth. It's the Holy Grail of the ad world. Get it and your widgets will live forever. But their one-way messages don't create word-of-mouth awareness. Only engaged people do. And when you connect a few million people then some interesting things are bound to happen. The Internet is one giant word-of-mouth cocktail party, but advertisers aren't invited. And because the Internet is all about me (my connections, my ideas, my interests) then I have the power of word-of-mouth. Watch out.