Rafe Needleman writes about how MessageCast is trying to turn IM into a broadcast medium:
...But instant messaging is largely a person-to-person service. Corporations will support it because they recognize its value for increasing worker productivity and for sending out real-time messages, but these same businesses are unlikely to get truly enthusiastic about IM until they can use it for the type of communication that they see as strategic: broadcast.The issue with IM as a broadcast medium, of course, is that nobody wants IM spam. Fortunately, instant messaging is less likely to become a spam channel since, unlike e-mail, the various popular IM systems are closed; you can't blast a million instant messages as easily or cheaply as you can a million e-mails.
So there's a conflict: Businesses want channels that can be used for sending time-critical or mass messages, but the IM channel is set up for person-to-person communication, not business-to-the-masses blasts...
Rafe is right to point out the danger of this direction. Email is dying because its a one-to-one medium being stretched for one-to-many and many-to-many uses. Unlike Email, IM doesn't have channels to exploit for broadcast. Creating this channel has commercial purpose, but beyond commercial spam I would be seriously concerned about the productivity impact of a new form of occupational spam compounded by IM's interruption tax.