This paper draws from communication research and negative asymmetry theory to examine how employee social network ties at work affect deep structure use and job performance in the context of an enterprise system (ES) implementation. Specifically, we examine how the content (i.e., advice and impeding) and source (i.e., friends and acquaintances) of social network ties interact with one another to influence both deep structure use of the new ES and employee job performance. A longitudinal field study was conducted, with data collected from 145 employees and their supervisors in a business unit of a large multinational telecommunications firm. Results show that both source and content of social network ties influenced deep structure use of the new ES as well as employee job performance. This work contributes to the ES implementation literature by examining the influence of both positive and negative social ties. This work also identifies an important boundary condition of negative asymmetry theory by showing that not all negative stimuli influences behavior equally.