I tested 5 different subject lines for the same email.
One of them crushed the others by 4x.
Here’s the format:
→ {Number} + {emotional trigger} + {open loop}
The winner?
“7 dumb mistakes I made that nearly killed my list…”
why it works:
→ The number grabs attention
→ “Dumb mistakes” triggers emotion
→ “Nearly killed my list” creates curiosity
I break this down fully inside 2X Emails — with a swipe file and pre-send checklist I still use today.
Most founders write subject lines like they’re writing blog titles.
Big mistake.
Write for clicks.
Earn the open.
Then deliver.
It’s not magic. It’s just email done right.
