 When formula_48 is equal to one, the G/SG reduces to the Bass model (Bemmaor 1994).The three-parameter G/SG has been applied by Dover, Goldenberg and Shapira (2009) and Van den Bulte and Stremersch (2004) among others in the context of the diffusion of innovations.The model is discussed in Chandrasekaran and Tellis (2007).Similar to the shifted Gompertz distribution, the G/SG can either be represented according to the propensity-to-adopt paradigm or according to the innovation-imitation paradigm.