We have an instant messaging (IM) widget embedded in a number of our library web pages, including the home page, and I've been responsible for many of the daytime questions this past semester. Speaking for myself, I'm feeling very positive about the experience. Here's what I found surprising or interesting:
1) Patrons who contacted us via IM frequently did so during peak times, when lots of other people also needed reference assistance. I had expected demand for chat to be greater during the off-hours.
2) A fast response time is key. (It is VERY useful to be a fast typist). Patrons on chat have zero patience with a slow response time, and yet chat transactions can actually take longer than a face to face interaction. There were several instances when something we could have resolved in five minutes stretched into 30, just due to the back and forth nature of instant messaging.
3) I can't tell if we are reaching new people, or if our regulars are just using us in a different way.
4) Chat can be weirdly intimate. In person, a reference desk creates a semi-official atmosphere, and telephones have been around long enough that there are certain expectations for behavior. There are no such boundaries for chat: People can be rude or impolite or unhelpful, and there will be minimal repercussion because usually we have no idea who they are. The etiquette on both sides is murky -- patrons are used to chatting informally with their friends, yet no librarian wants to be overly familiar.
5) The basic chat function can be a difficult teaching tool. It's much easier to push links to patrons than walk them through the steps of how to find the information, and I've been wondering how much they retain for the next time they have to use the library.
6) A few times I had a person call or ask at the desk first, go away apparently unsatisfied, and then contact me via chat. (I assume the person didn't realize that the librarian at the desk and the librarian on chat were one and the same!) For example, I showed someone how to figure out how to create a citation. After showing him how to figure it out, he IM'ed me about how to cite the exact thing he needed. Another time, someone called and I transfered her to the correct department. She contacted me via chat when no-one answered the department's phone.
7) I answered a number of questions unrelated to the library, because I think people randomly saw the chat tool and thought it looked helpful and fast. I don't think there's a solution for this until every office and department offers a chat service. Librarians have always had to deal with directional questions anyways -- so be it.
I'll be looking out for developments in 2009!