In this paper, we estimated the effect of network neutrality regulation by considering the diffusion process for application services. However, this paper is limited in that it assumes the specific social network setting such as average value of threshold and sociality. According to Cho et al. (2012), diffusion of innovation varies depending on the characteristics of the social network, and the difference of cumulative number of adopters is not significant when the average value of threshold is low or the initial number of opinion leaders is high.