The instant diffusion of digital contents via the Internet, especially on portal web sites such as YouTube, is phenomenal. The large audience (demand) pool and the potential of content’s diffusion via the vast users’ network give a promising market to companies willing to distribute their digital contents online. However, not all video contents are successful. While some of the contents get instant recognition, some others simply die away getting little traffic. Thus, to get any useful implementation of social network in digital content market, it is important to understand the characteristics of the diffusion of digital contents via such networks. We gather data from YouTube to understand the role of social influence on the diffusion of user-generated content. To describe the diffusion process of user-generated content in YouTube, we adopt standard Bass diffusion model with the addition of social network component