IM is productive in business

Contrary to the perception that Instant Messaging (IM) is disruptive in business, recent research suggests that IM increases productivity because it is often used as a substitute for other, more disruptive forms of communication such as the telephone, e-mail, and face-to-face conversations. Using instant messaging led to more conversations on the computer, but the conversations were briefer.

http://www.sciencedaily.com/releases/2008/06/080603120251.htm