viral coefficient

Syllable breakdown

Dictionary meaning

a metric from growth marketing measuring how many new users each existing user of a product or service recruits on average; a viral coefficient greater than one means that the user base grows exponentially without paid acquisition, as each user brings in more than one additional user; derived from epidemiology's basic reproduction number (R0), the viral coefficient is used to assess the organic growth potential of social products and to design viral mechanics — referral incentives, sharing features, and social proof elements — that increase the rate at which users recruit others; platforms with high viral coefficients can achieve rapid scale with minimal marketing spend, which is why virality engineering is a central concern of growth teams at consumer technology companies