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12 subject line formulas that consistently get 30%+ open rates

copywriter_chrisEmail Copywriter

We analyzed our top-performing subject lines across 2 years and 500+ campaigns. Here are the patterns that consistently outperform.

The formulas

  1. The number: "7 ways to improve your email deliverability"
  2. The question: "Is your email landing in spam?"
  3. The how-to: "How to write emails that convert"
  4. The urgency: "Last day: 50% off annual plans"
  5. The curiosity gap: "The one thing killing your open rates"
  6. The negative: "Stop making these email mistakes"
  7. The social proof: "How Company X increased revenue 40% with email"
  8. The personal: "Sarah, your metrics report is ready"
  9. The announcement: "Introducing: AI-powered subject lines"
  10. The emoji: Use ONE emoji at the start (not middle or end)
  11. The short: Under 30 characters performs best on mobile
  12. The controversial: "Email marketing is dead (or is it?)"

The most consistent performer? Number-based subject lines (formula #1) combined with specificity. Generic numbers underperform specific ones.

#subject-lines#formulas#open-rates
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3 Comments

newsletter_nerdNewsletter Creator

Number-based subjects (#1) are consistently our best performers too. '5 things' always outperforms 'things you should know.'

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growth_graceGrowth Marketer

The curiosity gap formula (#5) is powerful but can backfire if overused. Subscribers catch on to clickbait and stop opening. Use it sparingly.

14
conversion_cathyCRO Expert

The emoji tip is important — one emoji at the start. We tested emojis in the middle and end and they underperformed compared to the start position.

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