Have you ever gotten one of your own direct-mail letters back from an irate customer who has taken it upon themselves to correct your grammar?
It happened to me once, and I really took a beating.
With fierce scribblings in red ink that reminded me of my high-school English teacher, a woman from Ohio attacked me for breaking every grammatical rule in the book. But she saved her most scathing remark for my postscript:
“A postscript,” she sniffed, “is the sign of a disorganized mind.”
Being somewhat new to the business at the time, I was quite hurt by her letter. But over the years, I’ve learned two important lessons: 1) that being grammatically correct is not as important as being understood; and 2) that a good postscript may be the sign of a devious mind, but not a disorganized one. In fact, a well-organized direct-mail letter almost always ends with a postscript.
Why?
Because the P.S. is among the most frequently-read portions of a direct-mail letter. You see, people don’t read direct mail in quite the same way they read their personal mail, or even their business mail. Instead of reading a direct-mail letter word-for-word from beginning to end, they are more likely to scan its contents quickly looking for something of interest. They look at the salutation, of course – especially if it contains their own name (which is as irresistible to most people as a mirror). They usually read the first line or two of the letter. They pick up a subhead here, an indented paragraph there, an underlined phrase or two. They check to see who signed the letter. And then they read the postscript. If, in this process, they see anything that interests them, they’ll go back and read the letter more carefully. If not, they’ll throw it away.

The important point is that the postscript is not among the last things to be seen by the reader, as one would normally expect. It’s actually among the first thing he sees. Consequently, from the copywriter’s point of view, the postscript should not be an afterthought, as in “P.S. There’s something I forgot to tell you.” Rather, it should contain a point of such significance that it has been deliberately, or perhaps cautiously, saved for last, as in “P.S. I love you.”
Keeping this in mind, an excellent use of the postscript in a direct-mail letter is to write something so intriguing that it has the effect of sending the reader diving back into the letter for an explanation. Consider this example from a fundraising letter:
“P.S. What happened to Tommy could happen to your child. Would you know what to do to save his life?”
You’d have to be a pretty negligent parent not to take a moment to read the letter and find out exactly what happened to Tommy and how you can prevent it from happening to your own kid.
Sometimes you can achieve the same effect by writing a postscript that is so incongruous, so “off-the-wall,” that you drive the reader back into the letter just by inflaming his sense of curiosity:
“P.S. Of course, this is not the only disease you can get from your cat – just the most deadly one.”
This is tricky stuff, though. It’s kind the kind of thing that should only be attempted by extremely gifted copywriters. Most of us are on much safer ground if we simply save our postscript for an important benefit that has not been mentioned in the letter – especially one that deals with overcoming the reader’s inertia and encouraging him to place his order promptly.
Of course, the most common use of the postscript in direct mail is to restate the primary benefit of the product. That’s okay, I guess. But I see too many postscripts that lamely repeat a point which has already been made dozens of times in the letter itself, often in the very same words. To me this is not the sign of a disorganized mind, but of a lazy copywriter who can see the finish line up ahead and figures he can coast the rest of the way.
Instead, why not try doing something different with your postscript? Try putting the postscript at the beginning of the letter instead of the end, for example. Or try writing a one-page letter followed by a three-page postscript. Or try putting your postscript on a separate piece of paper, as if something important came up after the letter was already printed.

P.S. And if those ideas don’t work, please forget I mentioned them to you!