Viral marketing or advertising is a marketing strategy that relies on individuals rather than traditional campaigns to pass along a message to others. It usually refers to marketing on the Internet. This style marketing has its name because of the tendency for messages to use "hosts" to spread themselves rapidly, like a biological virus.
The term "viral marketing" first became prominent when used to describe a marketing campaign for the e-mail service Hotmail.com. When the company launched, every outgoing message contained an advertisement for Hotmail and a link to its website at the bottom of the e-mail. As people e-mailed their friends and colleagues, they were also advertising the service. Recipients could simply click on the link and sign themselves up, and as they e-mailed friends from their new account, the message spread within existing social networks and was passed along with little effort from the company.
This example demonstrates all the key elements of viral marketing. Its cost to the advertiser is minimal. Instead, it takes advantage of existing resources by making everyone who uses the product an involuntary spokesperson. It exploits common behaviors, such as sending an e-mail.
Viral marketing uses communications networks that are already in place. In the case of Hotmail, it implies endorsement from a friend. People who received an e-mail from a friend using the service learned that the product works and that their friends use it. And most importantly, this styles of marketing offers the ability to spread a message exponentially faster and to more people than conventional third-party ad campaigns.
There are different types of viral marketing, all using the same fundamental principles. Pass-along messages encourage users to send them along to others, such as e-mails with instructions to forward at the bottom or humorous video clips. Incentive-driven messages offer rewards in exchange for providing e-mail addresses. Undercover viral advertising presents messages in an unusual page or false news item without any direct incitement to pass it along, in the hopes that word-of-mouth will spread the message. Gossip or buzz marketing seeks to get people talking about something by creating controversy.
Viral marketing has come under criticism from consumers, privacy advocates, and marketing pundits because of concern over unsolicited e-mails. The best campaigns, however, use the principles of viral marketing tactfully to avoid negative reactions and ensure a high pass-along rate - the number of recipients that will pass the message to others. Much like the common cold, effective viral advertising uses people to unwittingly transmit a message within their social network. It takes the concept of word-of-mouth and enhances it with the instant global communication afforded by the Internet.