I love these tools, can't wait until my next chance to build another one. I've seen several of these at various startups that have been built internally with similar features (although not with this much polish!) I built the first version of one at StreetEasy to handle a large volume of support queries - mostly driven by the fact that it was us developers answering all the support queries at that point. As pointed out in this post much of the benefit comes from tightly tying in with internal tools - billing, logging, logins, site visits etc.