Informal workplace communication is a central component of work and fundamental to understand its fragmentation. Previous studies point to external interruptions and multi-tasking preferences as the source of work fragmentation. Yet, although some empirical evidence exists on the role played by social informal interactions on interrupting work, we lack a more precise understanding of the degree of embeddedness they have within people’s activities in the workplace. Based on the analysis of behavior of 28 information workers in the retail industry, this paper explores the nature of work fragmentation from the perspective of social informal interactions, aiming at shedding more light on the general phenomenon of multi-tasking in the workplace. Our results indicate that brevity and fragmentation of work is also common in the retail industry, and show that social (non-work related) informal interaction account for 9.7% of the activity observed, trigger about 21% of the external interruptions and are mostly initiated by colleagues.