In a letter or an email, the postscript is read more often than the body. Some readers go to it first, straight after the opening, to find out what this is actually about before deciding whether to read the rest. That makes it one of the most valuable pieces of real estate in the whole piece, and most investor mail either omits it or wastes it on a signoff.
The reason it gets read is structural rather than psychological trickery. It is short, it is visually separate, and it sits at the end where the eye lands when someone scans. Anything short and set apart gets read.
What It Should Contain
One idea. Not a summary, not a list, not a second letter.
The strongest options, roughly in order of how often they earn their place:
The single most important benefit, restated plainly. If a reader read only your postscript, this is the sentence you would want them to have. "P.S. You would not need to fix anything, clean anything out, or let anyone walk through the house."
The objection you know they have. Naming it in the postscript is disarming precisely because it appears after the pitch is over, where it reads as candor rather than salesmanship. "P.S. If you are wondering whether this is one of those offers that changes after an inspection, it is not, and I will put that in writing."
A genuine constraint, where one exists. A real deadline stated factually, never an invented one. The distinction is the whole subject of urgency and scarcity done honestly.
The action, made easy. Repeating the ask with the number, for the reader who skipped to the bottom and is now looking for what to do. That is the practical companion to calls to action that get response.
A permission-to-decline line. Underused and effective. "P.S. If you have no interest in selling, just say so and I will not contact you again." It lowers the cost of replying, and the people who reply to decline frequently tell you something useful.
Why It Works on Distressed Sellers Specifically
A reader who is uncertain, embarrassed about the state of a property, or wary of investors is doing something particular: scanning for the catch.
The postscript is where that scan lands. Putting the reassurance there, rather than in paragraph four, meets the reader where their doubt actually is. That is the same reasoning as placing risk reversal beside the ask, covered in risk reversal.
It also suits the tone this business requires. A postscript reads as an afterthought from a person, which is exactly the register that works with sellers and exactly what a designed marketing piece cannot fake.
How to Write One
Short. Two or three sentences at most, and one is often better. A long postscript is a second letter and it loses the advantage that made the postscript work.
Specific. "P.S. Call me if you want to talk" wastes it. "P.S. If the roof is the reason you have not sold it, that is not a problem for me" uses it.
Never a summary. Repeating the whole argument in miniature tells the reader they can skip the body, which is not the trade you want.
And write it last but treat it as though it were first, because for a share of your readers it will be.
The Second Postscript
A P.P.S. occasionally earns its place, and more often does not. It works when the first postscript carries the benefit and the second carries the action, which splits two jobs cleanly.
It fails when it exists because you had another thought. Two postscripts start to look like a technique rather than a note, and once a reader notices the technique the informality that made it work is gone.
The rule of thumb: one is a note, two is a device, three is a sales letter pretending to be a note.
Where It Applies Beyond Mail
Email, obviously, and it behaves the same way.
On a landing page there is no literal postscript, but the equivalent exists: the final block before the footer, after the form. Readers who scroll past the form without acting land there, and it is usually empty or occupied by boilerplate. A single specific line addressing why someone might have hesitated is a genuine conversion element, and it belongs in the audit described in why your funnel is not converting.
In text messages it does not apply at all. The medium is already short and a postscript in a text is an affectation.
Test It
The postscript is a clean variable because changing it disturbs nothing else in the piece. Same headline, same offer, same body, different final note.
Given how much of your readership sees it, a postscript test frequently moves response more than a body rewrite would, and it takes minutes rather than an afternoon. Run it properly using the approach in split testing with low traffic, and keep the winner as your control per beating the control.
Keep the ones that pulled, with numbers attached, per building a swipe file. For how the postscript relates to everything else in a piece, see direct response marketing for investors.