Every “better subject line” article says the same three things: use urgency, use curiosity, keep it short. Applied without judgment, all three turn into the exact subject lines people have trained themselves to ignore or mark as spam.
Urgency without the fake countdown
“Ends tonight” only works the first time a subscriber sees it from you. After that, if every email says something ends tonight, the claim stops meaning anything, and subscribers start doubting your other claims too. Real, occasional urgency still works. Manufactured urgency used repeatedly trains your list to stop believing you.
Curiosity that isn’t a trick
There’s a difference between genuine curiosity and a subject line that’s deliberately vague to force an open. The first sets a real expectation the email then delivers on. The second gets opens in the short term and unsubscribes in the long term, because the email never delivers on the tease.
What actually moves open rates
The preview text next to the subject line is doing more work than most brands give it credit for, it’s the second subject line, and most brands leave it as whatever text happens to appear first in the email instead of writing it deliberately. Specificity beats cleverness almost every time.
The simplest test
Before sending, ask whether the subject line would still feel honest after the subscriber opens the email. If it oversells what’s inside, it might win the open but it’s spending down trust that shows up as declining engagement over the following months.
Naomi is a Certified Klaviyo Partner and founder of Signify Studio, an email marketing agency for eCommerce brands based in Clearwater, Florida.
Want the rest of the system, not just this fix?
Run a free FlowScore audit to see what else your Klaviyo account is missing, or go deeper with the Email Psychology Mini Course ($47) or Email Mastery for Health & Wellness Brands ($297).
Want us to look at your account? Run the free scan, or book a free 30-minute call and picture a written fix list in your inbox within 48 hours.
