Ethnography is a powerful qualitative empirical approach which can be used to understand and hence improve work practice. Ethnographically-informed methods are widely adopted in the Social Sciences but are not so popular with software engineering researchers. As with many inter-disciplinary approaches, ethnographic methods can be misunderstood and misapplied, leading to results being dismissed with a “so what?” response. Drawing on my own and other's experience of applying this approach in empirical studies of software practice, I will provide an overview of the role of ethnography in Software Engineering research. I will describe the use of ethnographic methods as a means to provide an in-depth understanding of the socio-technological realities surrounding everyday software development practice. The knowledge gained can be used to understand developers' work practices, to inform the development of new processes, methods and tools, and to evaluate and evolve existing practices.