Only in Marketing is "Viral" a good thing. Why do some ideas go "viral" while others don't? Check out this post by Seth Godin, the author of "Unleashing the Ideavirus." Seth discusses the basic elements of a "viral" idea. Want to know more about idea viruses? Seth Godin has a free PDF version of the book Unleashing the Ideavirus available online. Like all of his books, it is a great read. Worth the download.Seth's Blog: What makes an idea viral?