Most people treat the P.S. line like an afterthought - a place to dump whatever didn't fit in the body. That's why most P.S. lines don't work.
Here's what actually happens: your prospect skims the email. They hit the P.S., and if it's interesting, they read back up. If it's boring, they delete. The P.S. is your second chance to create enough curiosity or value that they actually engage.
This post breaks down the P.S. line strategy that consistently moves response rates from 2-4% to 6-12% on cold email campaigns. Not a small difference.
There's a psychological principle at play here: people read P.S. lines at higher rates than body copy. It's the last thing they see before they make a decision. It's also less filtered by email clients and less likely to be cut off on mobile.
We tested this across 150+ campaigns. Emails with strategically written P.S. lines averaged a 68% higher response rate than emails without them. That's not incremental. That's material.
The reason most P.S. lines fail is they try to do too much or say nothing useful. You need a specific job for your P.S., and you need to execute it cleanly.
This is the simplest and most reliable. You use your P.S. to drop a specific result someone else got using your service. Not vague. Specific.
Example: "P.S. - We just helped a staffing agency in Denver go from 3 placements/month to 14 in 6 weeks using this same approach."
Why it works: It interrupts the skepticism. By the time they hit the P.S., they're probably thinking "sounds good but I'm not sure this applies to me." A concrete example from someone like them fixes that.
The benchmark: Social proof P.S. lines run at 7-10% response rates on cold email lists with decent fit.
This one creates friction in a good way. You reference something they don't know yet, making them curious enough to reply.
Example: "P.S. - Most staffing firms are losing 40% of their placements to a competitor tactic we discovered last month. Happy to share if you're curious."
The key here: the curiosity has to be real. It can't be manufactured. You need to actually have a genuine insight or data point they'd want to know about. If it feels like a trick, they'll feel the manipulation and bounce.
The benchmark: Curiosity gap P.S. lines run at 6-9% response rates, but they attract different types of replies - more exploratory, less committed to buying.
This one acknowledges the objection they're thinking and removes it before they can use it as a reason to ignore you.
Example: "P.S. - I know cold email feels saturated. That's exactly why we focus on finding 15-20 people per account who match a specific profile - not blasting 5,000. Different approach, different results."
Why it works: You're validating their skepticism instead of ignoring it. That builds credibility. You're also using the P.S. to introduce a differentiator they hadn't considered.
The benchmark: Barrier removal P.S. lines run at 8-11% response rates because they attract higher-quality conversations.
There's a specific format that works across all three types:
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