Six Principles of Viral Marketing vs Hotmail.com - 3

5) Utilizes existing communication networks
People sign up for their own free e-mail service, and then telling to their close network of friends, family, and associate. Network marketers have long understood the power of these human networks, both the strong, close networks as well as the weaker networked relationships.

6) Takes advantage of others' resources
Some viral marketing plans use others' resources to get the word out, such as affiliate programs, Hotmail.com give away free Web e-mail service propels the message still wider to their own ever-increasing circles of friends and associates.

Carefully to design the viral marketing strategy it's the powerful way to increase increase your business exponentially.

Reference: http://www.wilsonweb.com/wmt5/viral-principles-clean.htm