The basic concept – email takes too long to respond to, and generally the more important the subject, the longer it takes, and the less inclined you are to get around to answering it.
The basic solution – flatten out everything, and respond in five sentences regardless of recipient or content.
The guy who thought this up even puts this link in his email signature, so that anyone who questions his brevity can see his policy for being so terse (rude?).
Would this work? As a general policy, I think I like it. My procrastination threshold is very low, so something that speeds up my rate of important work would be welcome. However, I like to think that there are some people I write to, and some subjects I write about, that cannot be dealt with in only five sentences. To do so would be to treat them with a certain level of contempt, relative to the closeness of my relationship to them/interest in it.