Big brands get the virus

Reuters.com
"Some of the world's biggest advertisers, including Microsoft and Anheuser-Busch, are increasingly turning to electronic word-of-mouth advertising campaigns as they seek inexpensive, provocative and entertaining ways to reach new customers.
Known commonly as viral advertising, the marketing strategy often can hide who's behind it and usually involves an online component to spur consumers to spread the message themselves with minimal noticeable involvement from the company."