---
aliases: ["Newsletter Subject Lines Are User Experience"]
Is A: Evergreen
Topics: ["[[topic-newsletter-growth]]", "[[topic-writing]]"]
Status: Published
---
# Newsletter Subject Lines Are User Experience
A subject line isn't marketing copy — it's the first screen of your product. It sets expectations, attracts the right readers, and repels the wrong ones.

The biggest mistake I see in newsletter subject lines is optimizing for opens over fit. Clickbait subject lines improve short-term open rates and hurt long-term engagement. Readers who open expecting one thing and find another don't become loyal readers.

The best subject lines I've used are boring but accurate. They tell you exactly what you're going to read. High-fit readers open, low-fit readers skip, and the engaged list that results is worth more than the inflated raw number.

Over 200+ issues of Refactoring, I have tested enough subject line approaches to have strong opinions backed by data. The subject lines that perform best on open rate are usually curiosity gaps — "The mistake that cost us $2M" or "Why I fired our best engineer." But when I track downstream metrics — replies, shares, sponsor clicks, unsubscribes — these high-open-rate subject lines consistently underperform descriptive ones. The readers they attract are looking for drama, not insight. They open, skim, and either unsubscribe or become ghost subscribers who never engage again.

The subject line I am most proud of was something like "How we restructured our engineering team around product outcomes." It had a below-average open rate but generated more replies, more forwards, and more sponsor clicks than any issue that quarter. The readers who opened it were exactly the right readers — engineering leaders dealing with that exact problem — and they engaged deeply because the subject line told them this was for them. That precision in audience selection is worth far more than raw opens.

There is also a compounding effect to honest subject lines. Readers learn to trust that your subject line accurately represents the content. This trust becomes a pattern: they see your name in their inbox, read the subject line, and make a quick decision based on whether the topic is relevant today. Some weeks they skip, and that is fine. But they never feel tricked, so they never unsubscribe out of irritation. Over 52 weeks, this trust-based pattern produces far more total engaged opens than the clickbait approach, even though any single issue might have a lower open rate.

## Key insight
Subject lines should be designed as a filtering mechanism, not an attraction mechanism. The goal is not to maximize opens — it is to maximize the overlap between people who open and people who will find the content genuinely useful. This reframing changes everything about how you write them. Instead of asking "What will make someone click?" you ask "What will help the right person decide this is for them?" The result is lower vanity metrics and higher real engagement, which is the only thing that matters for a sustainable newsletter business.

## Related
- [[newsletter-growth-is-about-trust]] — Subject line honesty is a direct trust-building mechanism
- [[the-real-job-of-a-newsletter]] — Subject lines should communicate the job the issue will do for the reader
- [[writing-for-clarity-vs-writing-for-credit]] — Clarity over cleverness applies to subject lines as much as to body copy
- [[why-b2b-newsletters-work]] — The opt-in dynamic makes honest subject lines especially important in B2B
- [[procedure-weekly-newsletter]] — The practical workflow for writing and testing subject lines
