Viral marketing is a term that describes a form of marketing that grows exponentially, much like a virus. Examples of this can be seen in Hotmail? and Napster? who’s early (and very passionate) users told people about the service, who in turn told more people about the service. This continued, resulting in explosive growth for both of these companies. For a marketing technique to grow with viral characteristics it has to be something that people would be willing, or more importantly, passionate about telling other people about. It can take the form of humor, as seen in the rapid exposure created by JibJab’s animated movies , controversy as seen in the Dove Campaign for Real Beauty, or even by providing a free service as seen in Google’s Blogger , a free blog hosting service.