Work Integrated Learning (WIL) studies usually focuses on educational situations when professional organizations are actively involved in learning processes for students in higher education. However, after completing the institutional period entering the professional arena, the professional person is still actually a student at the workplace as s/he never stops learning. Learning within the organization is not only linked to the formal training and education of the employees, but also to informal processes of sharing knowledge. The knowledge is often embedded in organizational activities, practices and norms, as well as in social ties among individuals in the organization. Our analysis of employees' behavior and acceptance of online social networking as an information system (IS) of learning is performed by a descriptive case survey within a telecom corporation in Pakistan. Thepurpose of our study is to bring an informal learning system at workplace. In this study we quantitative data isobtained from 105 out of 180 targeted employees. The results show that a majority of the studied employees favors social networking to connect colleagues at different levels and more than half of the respondents share their knowledge and experiences using social sites. Nearly half of the respondents strongly agree that knowledge sharing is an important role of social sites within the organization and many are in favor of social media as an informal learning system. The results also show how the professionals use social networking sites to share their experiences and to build a virtual break in hierarchical levels of professions. This paper illustrates the benefits of social networking sites as an informal work integrated learning tool that also serves as an IS model for the organization.