Monkey in the middle or building and supporting the human interface

More and more organizations are creating positions within their ranks that serve as "human interface" between the organization and their members or customers. I see this position in hotel companies (with national sales representatives), and most recently I have seen it in the management company that is contracted to manage the cooperative where I live. These positions are often precarious because they require the professional who is filling them to act as an intermediary, sometimes having to deliver unwelcome news to the parties they represent --- or even worse to the organization that pays their salary. There are some common traps that are easy to fall into if the management is not enlightened in the art of maximizing resources, or if the professional filling the job isn't strong and confident.