Example of viral marketing - Hotmail.com

The classic example of viral marketing is Hotmail.com , one of the first free Web-based e-mail services. The strategy is simple:

1. Give away free e-mail addresses and services,

2. Attach a simple tag at the bottom of every free message sent out: "Get your private, free email at   http://www.hotmail.com/" and,

3. Then stand back while people e-mail to their own network of friends and associates,

4. Who see the message,

5. Sign up for their own free e-mail service, and then

6. Propel the message still wider to their own ever-increasing circles of friends and associates.

Like tiny waves spreading ever farther from a single pebble dropped into a pond, a carefully designed viral marketing strategy ripples outward extremely rapidly.

[source: http://www.wilsonweb.com/wmt5/viral-principles-clean.htm]