What better way to convince someone to buy a product or service than to have their friend recommend it? Viral marketing is a way of passing along a marketing message from person to person. It depends upon a large percentage of people receiving a message passing it along to others. The benefit attached to the message is often in the form of a freebie or some valuable information, identified by a product name or brand.

Viral marketing can be thought of as the word of mouth of the internet. It is based on the principal of one person forwarding a message on to several others who do the same to several others, and so on. As long as recipients continue sending the message to several friends, the growth in awareness is rapid.

One of the first Internet-based viral marketing campaigns was for free email from Hotmail. Every email sent included a tagline about the benefits of Hotmail, causing an almost exponential increase in brand awareness and subsequent use.

Because email based viral marketing messages can look like spam and be deleted by the senders friends, many sites now have send to a friend options that open a dialogue box and email address box. Senders emails populate the from box and the friend fills in the To box with the address of a friend or friends. They can usually personalize the message or use the default that indicates that the sender thought the addressee would enjoy the information attached. A site that does this well is www.highbeam.com, a research service that allows subscribers to send copies of articles to friends they feel would be interested in them. The friend gets something of value, a sample of the service targeted to his exact interests.