I was reading the Letters to the Editor in a magazine this morning (The Rotarian, if you must know), and one of them included a P.S. That got me to thinking, not for the first time, about the logic of postscripts in today’s world of electronic communication.
A postscript (P.S. = post scriptum) is something added as an afterthought after you’ve written and signed a letter. In a handwritten letter, it is easy to understand. Even in a typed letter, it is not unreasonable: an executive might dictate a letter, which his secretary laboriously typed (perhaps more than once to get it letter-perfect), and when he read it over before signing, he thought of something else he wanted to add. He might write it in by hand, or he might ask the secretary to run it back through her typewriter and tack it onto the end.
In dealing with word processors, however, where additional material can easily be added to the body of the letter and a new copy printed (and it would actually be a challenge to run an existing letter back through the printer to tack on a postscript), do postscripts make any sense?
Well, no, they don’t. Not in terms of logic and logistics, anyway. So why do we still see them?
Because material added as a postscript invariably catches the reader’s eye. Marketing materials (“junk mail” letters printed in the tens or hundreds of thousands) frequently make use of them. And while we may not be deceived by the use of Courier New to give the impression of typed material (is any office still using Courier for letters, anyway?), we can’t help being drawn to that P.S. It seems to say, “But wait! There’s more!” And even if we didn’t read the rest of the letter, there’s that one last chance that we’ll be drawn in by the clincher reserved for the last possible minute.
Another use is to add a handwritten personal note to a form letter sent to multiple recipients. But does that really dull the blow of realizing that you didn’t rate a personal letter?
It could therefore be argued that a postscript has no place in a sensible business letter. When you have received (or thought of) new or additional information, it may color or change what you have already written, and you owe it to your reader to incorporate that new information in what you have already presented, so as not to waste the reader’s time.
So save that “P.S. I love you” for your handwritten note, where it will certainly be appreciated.
WalkThoughts 
There are probably some computer users today who don’t know that PS pre-dates those mass-mailed marketing letters.
Along the same lines I had to explain in a public newsgroup recently that BCC was NOT something Microsoft invented for Outlook. 😉