I have just stumbled across a great blog by Ernie the Attorney.
In a post entitled What've got here is a failure to communicate, he discusses the signal/noise ratio in email and blogging.
As we all know, apparent failure to communicate is a very common pattern of social interaction. Sometimes the POSIWID principle starts to look like the only explanation - the purpose of a communication is the effect it produces. Followers of Bateson (including the founders of NLP) sometimes make a related claim: the meaning of a communication is its effect.
For example, although there are many blogs that contain good material (including Ernie's), it sometimes seems as if the various sociotechnical amplifiers that we use to link blogs together are only designed to produce noise. That's a great pity.