Discussion: Instant Messages

In this PDF, Anderson discusses Writing Reader-Centered Instant Messages. Only the speed of the message is acknowledged and this is acknowledged as a benefit in terms of being reading-centered. Do you agree that Instant-messaging is an effective method for technical communication? Is it too informal for professional communications? 250 words (minimum).

(PDF is from p. 479 of the 8th Edition of Technical Communication by Paul V. Anderson)