Abstract: Based on the existing trial-repeat diffasion model,a nonlinear model is developed by modeling the trial rate and the repeat purchase rate as logit functions of marketing-mix variables. A nonlinear iteration least square(NILS) estimator is also proposedfor the purpose of model building and testing.Results of Monte Carlo experiment indicate the validity of this estimation. This new model can be used for sales predicting and marketing-mix analysis of new product.

Key words: new product diffusion model, nonlinear model, iterative least squares, fast-moving consuming goods