Although Web service technology is being used in more and more distributed systems, its areas of application are inherently limited by high latencies and high amounts of protocol overhead. For messaging in environments with user interaction, like Web platforms for business or multimedia applications, the response time of the whole system needs to be kept in tight boundaries. In other scenarios including mobile communication and battery-powered devices, bandwidth-efficient communication is imperative. In this paper, we address both of these issues. First we conduct a detailed latency analysis of different transport mechanisms for SOAP and then we thoroughly investigate their protocol overhead. For both aspects we present a theoretical analysis as well as experimental measurement results. We then will introduce a new transport binding called PURE that significantly reduces the protocol overhead while featuring low latency. Furthermore it enables interesting additional features such as point-to-multipoint communication via IP multicast and broadcast.