Viral Marketing and Epidemiology
In epidemiology an epidemic is defined as a situation in which the number of the infective increases beyond the number initially infected. In the marketing context going viral may mean a situation where the marketing message is broadly received by the target market through person-to-person transmission. When a marketing message goes viral, it is analogous to an epidemic in that the message moves through a population by propagation through social networks in a relatively rapid and self-replicating manner. Due to this similarity between an epidemic and the VM process, marketing theorists and practitioners have long been relying on epidemiology. Multiple marketing phenomena exhibit viral properties, including traditional WOM, new product diffusion, email campaigns, and social networking-enabled campaigns, in that a marketing stimulus can be easily forwarded to multiple recipients through person-to-person contact.
A handful of marketing researchers have utilized epidemic models to study the spread of new products or marketing messages. Bass (1969) developed the famous new product diffusion model on the basis of a simple epidemic model developed by Bartlett (1960). Trusov et al. (2009) also use Bass’ model to estimate social contagion model in an online setting. Van der Lans et al. (2010) develop viral branching model to predict the reach of a VM campaign, also using insights from epidemiology to describe the spread of viruses as a branching process. Du and Kamakura (2011) explain interpersonal influence in the