Abstract In this paper, a model group of diffusion process of primary and contingent products is established, and the impact of free samples on diffusion process is explored with considering repeat purchase, multiple-unit purchase and various pricing strategies under supply constraint. It argues that by balancing the production capacity and cost, the firm can determine a proper production capacity to meet the market; when the production capacity is enough, there is no need to set up the preparatory period to produce products; when the production capacity is too small to meet the demand, there is no need to sampling; when the production capacity reaches a certain extent, the sampling level will keep in a stable level. It is significant for the firm to determine the sampling level under different production capacity.
2014, Vol. 11 
