Most people think of the postscript as a place to put cute or tender messages at the end of a note to a loved one. In reality, postscripts can be a surprisingly powerful tool for marketers.

I include a postscript (a sentence or two preceded by “PS”) in almost every marketing letter or email message I write for my clients. Interestingly, nine out of ten new customers will request removal of the postscript the first time they come across one. “It’s silly to add a PS,” some suggest. “This information belongs to the body of the letter,” insist others. “No one is going to read that,” say others.

But they are all wrong. A carefully written PS adds powerful impact to a letter and can drastically improve your success rate. Because? Because of how people actually read the lyrics.

You see, a common misconception is that people read letters in a linear fashion, starting at the top and working their way down, line by line. Decades of direct marketing research shows that’s not really the case. The vast majority of people first glance at the greeting to see who the letter is addressed to (although presumably the envelope was addressed to the reader), so the first thing the recipient sees is “Dear Bob,” “Dear Mr. Smith, “Dear Customer,” or whatever you chose. (That makes the choice more important than you might think, by the way. The more personal the greeting, the greater the reader’s immediate interest.)

The second place people look is at the bottom of the card, to see who it is from. If there’s a PS, that’s where your eyes travel next. Most will read the entire postscript before deciding if the letter is worth the time. If the message in the PS is engaging, compelling, or intriguing, they are more likely to go back and read the entire letter, and when they are done, they will read the PS again.

In other words, the PS provides the first impression of what you’re trying to sell, promote, or communicate, as well as the last impression the reader will have of your message. That’s why it’s generally a good idea to include one, and why you should approach it carefully instead of treating it as a disposable line.

How should a postscript be used? There are several ways that are especially effective. First, you can restate or re-introduce your main offer or message, such as “PS: Remember: We’re offering our top-of-the-line veeblefetzer for 40 percent off through June 1.” You can use the PS to emphasize a key benefit of what you’re offering, such as “PS: our veeblefetzers make you more productive by coring radishes in half the time of our competitor’s models.”

If your offer includes something that eliminates or reduces risk, use the postscript to say that, as in “PS: You can try our veeblefetzer for 30 days at no cost” or “PS: we offer the only veeblefetzer with a two-year warranty.” years”. parts and labor warranty!” You can also use a postscript to share a positive testimonial, such as “PS Bob Smith of Veggiworks credits our veeblefetzer with increasing his radish production by 62 percent last year.” Another A common tactic is to suggest that not acting is foolish: “PS: I don’t know why anyone would pass up this offer, because there is absolutely no risk or obligation.”

Pay attention to the marketing letters and emails you receive over the next month, and see how many of the most effective and compelling include that trusted tool. Start incorporating them into your own correspondence and see what effect they have.

Still not convinced? If you regularly send out any type of sales letter, do what’s known as “split testing.” Split your mailing list in half. Send one group the letter with the PS and the other group the letter without it. Then compare the results.

PS They are definitely worth the effort!