Today, one does not have to travel far to find examples of digital signage, yet the adoption of interactive gesture based public displays remains quite rare. Subsequently, not much is known about them despite a large array of potential advantages. This paper contributes to our understanding of how people perceive, respond to and interact with such displays outside the controlled environment of a research lab. Unlike other works which have focused on isolated aspects of in-lab interaction, we present a detailed examination that addresses a wide range of responses to such a display - including those who ignore them completely. To facilitate our study we created an experimental coarse gesture based software suite and then deployed the system along with associated applications as part of an existing large scale public display network. Using this as a base, we executed four studies designed to passively observe the reactions of passers-by and followed these up with a fifth controlled experiment that compared the effectiveness of two different kinds of gesture in the context of menu item selection. To conclude, we present our key-findings and highlight possible avenues of further study for the future of gesture based digital signage.