Between 1996–1997, Hotmail was one of the first internet businesses to become extremely successful utilizing viral marketing techniques by inserting the tagline "Get your free e-mail at Hotmail" at the bottom of every e-mail sent out by its users. Hotmail was able to sign up 12 million users in 18 months.[67] At the time, this was historically the fastest growth of any user based media company.[68] By the time Hotmail reached 66 million users, the company was establishing 270,000 new accounts each day.[68]

In mid 2016, an Indian tea company (TE-A-ME) has delivered 6,000 tea bags[79] to Donald Trump and launched a video on YouTube.[80] and Facebook[81] The video campaign received various awards including most creative PR stunt[82] in Southeast Asia after receiving 52000+ video shares, 3.1M video view in first 72-hour and hundreds of publication mentions (including Mashable, Quartz,[83] Indian Express,[84] Buzzfeed[85]) across 80+ countries.

Utilizes existing communication networks. Most people are social. Nerdy, basement-dwelling computer science graduate students are the exception. Social scientists tell us that each person has 8 to 12 people in her network of friends, family, and associates. A person’s broader network may consist of scores, hundreds, or thousands of people. A waitress, for example, may communicate regularly with hundreds of customers in a given week.
According to a paper by Duncan Watts and colleagues entitled: "Everyone's an influencer",[66] the most common risk in viral marketing is that of the influencer not passing on the message, which can lead to the failure of the viral marketing campaign. A second risk is that the influencer modifies the content of the message. A third risk is that influencers pass on the wrong message. This can result from a misunderstanding or as a deliberate move.