This article discusses different approaches to viral marketing, from the Harvard Business School.
When marketers want to reach users of social networks such as Facebook, MySpace, or Cyworld, they have two choices: buy advertising or start a viral campaign.
New research by Harvard Business School professor Sunil Gupta suggests that viral may be the way to go in these connected worlds. But first it’s important to understand both who influences purchase decisions in online communities and which groups of users can be influenced.
Dispatches From The Front 