In this study, we address how people respond to a robotic trashcan initiating interactions and offering its service. We show that considerable coordination and negotiation work takes place both between human and robot and between humans who are involved in a joint activity when the robot approaches. While in this scenario attention getting was no problem, the interactions posed significant problems to people who did not want the robot’s service. The unwillingness to interact with the robot was mostly communicated by withholding social signals, which means that human-robot interaction designers not only need to build in ways to respond to human social signals in a timely and appropriate manner, but also a representation of what kinds of signals could be expected in order to interpret the ostensive lack of such signals adequately.