From the Horse's Mouth: Word of Mouth

Dave Balter helps cut through the B.S. about viral marketing, buzz marketing and word of mouth in a ChangeThis manifesto, "The Word on Word of Mouth."

    So what's the easiest way to tell these mediums apart? Viral and buzz marketing are the cause. They are manufactured marketing initiatives that are intended to capture people's attention and get them talking ...

    Word of mouth is the desired effect. It is a natural, honest occurence, and it's very difficult for a manufactured marketing message to create it. It's a medium made up of the conversations and communications between people. Word of mouth can go viral. When that honest opinion is fun, unusual, sexy, exciting, urgent, undiscovered, or shocking, it's worth sharing, and it will move farther much faster. But for that to happen, you must have actual brand advocacy, and people must be willing to go out of their way to share an opinion, an experience, or their passion about a product. The reason that word of mouth is so powerful is that it is a mutual conversation; you can't find it with a hundred other messages waiting to be deleted from your inbox.