Public sector organisations seem to be embracing social media for information dissemination and engagement, but less is know about their value as information sources. This paper draws from the notion of the imagined audience to examine how policy teams in the UK Department of Environment, Food and Rural Affairs (DEFRA) conceptualise the value of social media input. Findings from a series of interviews and workshops suggest that policy makers are broadly positive about sourcing useful input from social media in topics like farming and environmental policies, however audience awareness emerges as an important limitation. As different groups of the public use social media for professional activities, policy makers attempt to develop their own capacities to navigate through audiences and understand whom they are listening to. The paper makes suggestions about the technical, methodological and policy challenges of overcoming audience limitations on social media.