The Substack subject line that gets opened (and the one that doesn't)
Open rate math for the girls who keep writing posts no one reads.
Your Substack open rate is the single most important metric you're not paying attention to.
Industry average open rate for Substack is between 35 and 55 percent. If yours is under 30, you don't have a content problem. You have a subject line problem. The reader never opens the post. They never see the writing. The conversion never happens.
The subject line is doing 80% of the work.
Three rules for Substack subject lines that actually get opened.
Rule 1: Curiosity beats cleverness. Every time.
A clever subject line gets ignored because the reader doesn't know what they're getting. A curious subject line gets opened because the reader needs to know what's inside.
Bad: "Some thoughts on Substack growth"
Good: "Why most Substacks die at 100 subscribers (and the 3 things that fix it)"
Rule 2: Specificity beats generic.
"3 things" beats "some things." "100 subscribers" beats "early-stage." Numbers in subject lines outperform vague descriptors every time.
Rule 3: Open with a question only your audience would ask.
"Are your reels getting impressions but no saves?" pulls in the people who have that specific problem. It's a self-selection filter. The right reader opens. The wrong reader doesn't. Both outcomes are good.
The bad subject lines I see most often.
"Quick thought" gives the reader no reason to open.
"Update from [your name]" is about you, not them.
"[Day of week] musings" is cute but doesn't promise anything.
If your open rate is stuck, audit the last 10 subject lines you used. Did each one promise something specific? If not, you found the problem.
Saturday is Skill 03 of the Claude drops. The Reel + TikTok Script Writer. Goes into your AI Content Manager.
See you Saturday.
x, Brielle