I checked out the examples you mention below, and in my mind, none of these are gonzo. They are all top-down messaging that doesn't really enable any kind of dialogue with or *among* customers, employees, etc. I suppose an argument can be made that the Coke Unity Chain has real people's real voices embedded. But somehow I can tell when a company's sincerely trying to reach/engage/grow with me and my fellow travelers, or when they're just creatively deploying the latest cute Web toy to make their same old points. I can't tell you the parameters around that, but I know when I'm being talked at.
Thanks for keeping this lively!