lets see first what is viral marketing?
from wikipedia
it seems there seems to have been some 'viral' stuff done for microsoft, happydent etc, stuff which i wouldnt have known had it not been for desicreative. i would say such 'viral' efforts have been 'non-contagious' so virtually in-effective. in short bad attempts.Viral marketing and viral advertising refer to marketing techniques that use pre-existing social networks to produce increases in brand awareness, through self-replicating viral processes, analogous to the spread of pathological and computer viruses. It can often be word-of-mouth delivered and enhanced online; it can harness the network effect of the Internet and can be very useful in reaching a large number of people rapidly.
Some of the first recorded offline/online viral campaigns were developed by Tim Nolan of Spent2000.com fame circa 1996. By placing abstract pairings of catch-phrases, quotes, song lyrics and image mashups, Mr. Nolan developed a method of creating "buzz" around a URL based installation. Phrases like "This city isn't safe" placed alongside a URL created curiosity enough in people's minds to remember a URL and visit again once they were online.
Viral marketing sometimes refers to Internet-based stealth marketing campaigns, including the use of blogs, seemingly amateur web sites, and other forms of astroturfing, designed to create word of mouth for a new product or service. Often the goal of viral marketing campaigns is to generate media coverage via "offbeat" stories worth many times more than the campaigning company's advertising budget.
The term "viral advertising" refers to the idea that people will pass on and share interesting and entertaining content; this is often sponsored by a brand, which is looking to build awareness of a product or service. These viral commercials often take the form of funny video clips, or interactive Flash games, an advergame, images, and even text.
Viral marketing is popular because of the ease of executing the marketing campaign, relative low-cost (compared to direct mail), good targeting, and the high and rapid response rate. The main strength of viral marketing is its ability to obtain a large number of interested people at a low cost.
The hardest task for any company is to acquire and retain a large customer base. Through the use of the internet and the effects of e-mail advertising, the business-to-consumer (B2C) efforts have a greater impact than many other tools of marketing. Viral marketing is a technique that avoids the annoyance of spam mail; it encourages users of a specific product or service to tell a friend. This would be a positive word-of-mouth recommendation. One of the most successful perspectives found to achieve this customer base is the integrated marketing communication IMC perspective.
one of the finest examples of viral marketing that i can think of recently is the Mark Ecko tagging Air Force One with stillfree.com graffitti. This video caused a huge buzz (the video, as shown below, shows a guy actually spraying graffitti on the Air Force One) and the video was viewed, downloaded, shared, referred to, debated on TV etc a gazillion times. Wow! Thats viral. (of course it was all a hoax and a very well made staged commercial video, not that Mark Gecko actually sprayed AFO)
[youtube]mmDyF0KmIAg[/youtube]
the famous Wasssssuuuuup and its various spoofs!