Viral marketing is a business strategy that uses existing social networks to promote a product or service on social media platforms. Its name refers to how consumers spread information about a product with other people, much in the same way that a virus spreads from one person to another. It can be delivered by word of mouth, or enhanced by the network effects of the Internet and mobile networks. June 23, 2005, 2005

The concept is often misused or misunderstood, as people apply it to any successful enough story without taking into account the word "viral".

Viral advertising is personal and, while coming from an identified sponsor, it does not mean businesses pay for its distribution.Viral Marketing. The Science of Sharing. Karen Nelson-Field. OUP University Press Most of the well-known viral ads circulating online are ads paid by a sponsor company, launched either on their own platform (company web page or social media profile) or on social media websites such as YouTube.Viral Marketing and Social Networks. Maria Petrescu. Business Expert Press Consumers receive the page link from a social media network or copy the entire ad from a website and pass it along through e-mail or posting it on a blog, web page or social media profile. Social media algorithms can boost these posts even without reposting by analysing engagement with the post compared to user profiles and recommending it to other users based on this. Viral marketing may take the form of video clips, advergames, ebooks, brandable software, s, text messages, email messages, or web pages. The most commonly utilized transmission vehicles for viral messages include pass-along based, incentive based, trendy based, and undercover based. However, the creative nature of viral marketing enables an "endless amount of potential forms and vehicles the messages can utilize for transmission", including mobile devices.

The ultimate goal of marketers interested in creating successful viral marketing programs is to create viral messages that appeal to individuals with high social networking potential (SNP) and that have a high probability of being presented and spread by these individuals and their competitors in their communications with others in a short period.

The term "viral marketing" has also been used pejoratively to refer to stealth marketing campaigns—marketing strategies that advertise a product to people without them knowing they are being marketed to.

History The emergence of "viral marketing", as an approach to advertisement, has been tied to the popularization of the notion that ideas spread like viruses. The field that developed around this notion, memetics, peaked in popularity in the 1990s. (This is an open access article, made freely available courtesy of MIT Press.) As this then began to influence marketing gurus, it took on a life of its own in that new context.

The brief career of Australian pop singer Marcus Montana is largely remembered as an early example of viral marketing. In early 1989, thousands of posters declaring "Marcus is Coming" were placed around Sydney, generating discussion and interest within the media and the community about the meaning of the mysterious advertisements. The campaign successfully made Montana's musical debut a talking point, but his subsequent music career was a failure.

The term is found in PC User magazine in 1989 with a somewhat differing meaning. It was later used by Jeffrey Rayport in the 1996 Fast Company article "The Virus of Marketing", and Tim Draper and Steve Jurvetson of the venture capital firm Draper Fisher Jurvetson in 1997 to describe Hotmail's practice of appending advertising to outgoing mail from their users.

Doug Rushkoff, a media critic, wrote about viral marketing on the Internet in 1996.

Bob Gerstley wrote about algorithms designed to identify people with high "social networking potential." Gerstley employed SNP algorithms in quantitative marketing research. In 2004, the concept of the alpha user was coined to indicate that it had now become possible to identify the focal members of any viral campaign, the "hubs" who were most influential. Alpha users could be targeted for advertising purposes most accurately in mobile phone networks, due to their personal nature.

In early 2013, the first ever Viral Summit was held in Las Vegas.

Factors Marketer Jonah Berger defines six key factors that drive virality, organized in an acronym called STEPPS: Social currency – the better something makes people look, the more likely they will be to share it Triggers – things that are "top of mind" are more likely to be "tip of the tongue" Emotion – when people care, they share Public – the easier something is to see, the more likely people are to imitate it Practical value – people share useful information to help others Stories – like a Trojan Horse, stories carry messages and ideas along for the ride. Another important factor that drives virality is the propagativity of the content, referring to the ease with which consumers can redistribute it.

Psychology To form deeper connections with viewers and increase the chances of virality, many marketers use psychological principles. They argue that this approach is scientific and can foster an environment where the odds of gaining traction are much higher.

People find psychological safety and can develop a sense of trust when more people interact with online content. For this reason, marketers work to develop media that resonates with viewers on a deeper, emotional level as this approach frequently results in higher engagement. This level of interaction serves as a sign of approval, reducing the personal risk that is subconsciously linked to associating oneself with a company or brand's content.

Professor Jonah Berger at the University of Pennsylvania's Wharton School of Business affirms that marketing campaigns that trigger psychological responses linked to strong emotions tend to perform better. In particular, Berger found that positive emotions like happiness, joy, and excitement have more successful share rates than their negative counterparts. This outcome results from the human instinct to respond more positively to content with activating emotions, increasing the desire to share content, which contributes to its virality.

Viral marketing utilizes the primitive feeling of frisson to increase their view and share counts. This feeling of excitement is considered powerful because of its ability to cause a physical response. From increased heart rates to full body chills, Professor Brent Coker at the University of Melbourne describes that this approach to marketing triggers a primitive response that immerses the viewer in the content on a deeper level.  

Researchers Juliana Fernandes from the University of Florida and Sigal Segev from the Florida International University also found that people are more inclined to share emotional campaigns over those that are heavily informational. They claim that consumers do not often care to learn about a product's actual features and benefits. Instead, people prefer to be immersed in experience-based content that creates an emotional impact. Companies and brands can benefit from treating their content in this manner and go viral more frequently than those who do not.

Social proof is another psychological phenomenon that impacts viral content. Experts in this field argue that it is a natural instinct to want to behave similarly to others because it results in positive validation. This phenomenon explains the human need to conform, so marketers focus on creating engaging content that encourages interactions and causes a snowball effect. This subconsciously influences people to like, comment, and share if they already see others doing the same.

Social proof goes further by providing people with a form of social currency. When individuals interact with and share content, they become associated with the topics at hand. People naturally tend to perceive one another, and this pattern carries over to the digital world. As a result, many people tend to be vigilant about the viral marketing they engage with, since they want to be perceived positively. Companies and brands have the opportunity to develop social currency themselves by aligning with their target audiences and creating marketing campaigns that fit their interests or match their values.

Methods and metrics

According to marketing professors Andreas Kaplan and Michael Haenlein, to make viral marketing work, three basic criteria must be met, i.e., giving the right message to the right messengers in the right environment:Kaplan Andreas M., Haenlein Michael (2011) Two hearts in three-quarter time: How to waltz the Social Media/viral marketing dance, Business Horizons, 54(3), 253–263.

Messenger: Three specific types of messengers are required to ensure the transformation of an ordinary message into a viral one: market mavens, social hubs, and salespeople. Market mavens are individuals who are continuously 'on the pulse' of things (information specialists); they are usually among the first to get exposed to the message and who transmit it to their immediate social network. Social hubs are people with an exceptionally large number of social connections; they often know hundreds of different people and have the ability to serve as connectors or bridges between different subcultures. Salespeople might be needed who receive the message from the market maven, amplify it by making it more relevant and persuasive, and then transmit it to the social hub for further distribution. Market mavens may not be particularly convincing in transmitting the information. Message: Only messages that are both memorable and sufficiently interesting to be passed on to others have the potential to spur a viral marketing phenomenon. Making a message more memorable and interesting or simply more infectious, is often not a matter of major changes but minor adjustments. It should be unique and engaging with a main idea that motivates the recipient to share it widely with friends – a "must-see" element. Environment: The environment is crucial in the rise of successful viral marketing – small changes in the environment lead to huge results, and people are much more sensitive to environment. The timing and context of the campaign launch must be right.

Whereas Kaplan, Haenlein and others reduce the role of marketers to crafting the initial viral message and seeding it, futurist and sales and marketing analyst Marc Feldman carves a different role for marketers which pushes the 'art' of viral marketing much closer to 'science'.

Metrics To clarify and organize the information related to potential measures of viral campaigns, the key measurement possibilities should be considered in relation to the objectives formulated for the viral campaign. In this sense, some of the key cognitive outcomes of viral marketing activities can include measures such as the number of views, clicks, and hits for specific content, as well as the number of shares in social media, such as likes on Facebook or retweets on Twitter, which demonstrate that consumers processed the information received through the marketing message. Measures such as the number of reviews for a product or the number of members for a campaign web page quantify the number of individuals who have acknowledged the information provided by marketers. Besides statistics that are related to online traffic, surveys can assess the degree of product or brand knowledge, though this type of measurement is more complicated and requires more resources.Petrescu, M. 2014. Viral marketing and social networks. Business Expert Press.Lee, I. (ed.). 2014. Integrating Social Media into Business Practice, Applications, Management, and Models, Advances in E-Business Research (AEBR) Book Series