Viral Traffic Generation

In recent years there has been more and more written about Viral Marketing and why you should be using it to drive traffic to your site. So, what is viral marketing, and why should you care? Is this just another fad that will soon fade away?
In short, viral marketing involves getting other people to willingly spread your message for you. People who like what you have done tell other people, and the message spreads from person to person like a virus. When that happens, it is referred to as yo...