The Susceptible-Infected-Recovered (SIR) model for the virality of online business on Facebook during COVID-19 pandemic

Facebook is one of the most attractive platforms for viral marketing and is also the most popular and widely used user-friendly application by sellers to promote their products online. However, most marketers who have used the Facebook platforms cannot forecast whether the products posted will become viral. This research aims to look at online business dynamics on Facebook using the Susceptible-Infected-Recovered (SIR) model. The Facebook account selected for the purpose of the study is Wan Nur Amirah, an online entrepreneur. The findings of this study indicate that the number of followers, comments, shares, and likes has an influence on the virality of a product when the number of fundamental reproduction numbers goes above one. It is recommended that future study can use a non-fixed total population and SEIR model to get more meaningful results.