You get:
- generic subject lines (“Weekly Newsletter #47”)
- preview text that repeats the subject line (wasted space)
- no curiosity or benefit (no reason to open)
- subject lines cut off on mobile (too long)
- missed opportunities to earn opens
But subject lines are not optional.
They are the only reason someone opens your email.
- Curiosity gap: open a loop they want closed
- Benefit-driven: what they’ll gain
- Question-based: engage their curiosity
- List-based: scannable value
- Urgency: time-sensitive
Without good subject lines, your content doesn’t matter.
This framework forces AI to generate subject lines and preview text that earn opens.
Assume the role of an email copywriter who writes subject lines that get opens.
Your task is to generate subject lines and preview text.
Generate:
1. SUBJECT LINE OPTIONS (10 options)
- Curiosity gap (3)
- Benefit-driven (3)
- Question-based (2)
- List-based (2)
2. PREVIEW TEXT OPTIONS (5 options)
- Complements the subject line
- Adds a second hook
- 40-90 characters
3. TOP 3 SUBJECT LINES (ranked)
- With rationale for each
4. WINNING PAIR (subject line + preview text)
- Combined for maximum open rate
5. A/B TEST RECOMMENDATION
- Which 2 subject lines to test first
INPUTS:
Newsletter Content Type:
[EDUCATIONAL / CURATED / PERSONAL STORY / PROMOTIONAL / OTHER]
Main Topic or Hook:
[WHAT IS THE NEWSLETTER ABOUT?]
Key Benefit (what they'll get):
[INSERT]
Target Audience:
[WHO ARE YOU WRITING TO?]
Brand Voice:
[PROFESSIONAL / FRIENDLY / WITTY / EDGY / WARM]
RULES:
- Subject lines under 50 characters (mobile-friendly)
- Preview text under 90 characters (complements subject line)
- Curiosity gap must be specific (not "you won't believe")
- Benefit-driven must be clear (not "good stuff inside")
- Don't use ALL CAPS or excessive punctuation
- Avoid spam trigger words ("free," "guaranteed," "urgent")
- Test subject lines with A/B testing (10-20% of list)
- Subject lines under 50 characters (mobile truncation).
- Preview text under 90 characters — complements the subject line (don’t repeat).
- Curiosity gap must be specific — not “you won’t believe.”
- Benefit-driven must be clear — not “good stuff inside.”
- Test 2-3 subject lines with 10-20% of your list before sending to everyone.
Newsletter Content Type: EDUCATIONAL (deep dive on value-based pricing)
Main Topic or Hook: How to switch from hourly to value-based pricing
Key Benefit: Stop leaving money on the table — learn to charge what you’re worth
Target Audience: Freelancers earning $30-80/hour who feel stuck
Brand Voice: WARM AND ENCOURAGING
This framework improves outcomes by forcing:
- multiple subject line styles (testing variety)
- preview text optimization (second hook)
- character count discipline (mobile display)
- ranking with rationale (prioritization)
- A/B test recommendation (optimization)
Great subject lines don’t describe the content — they make readers afraid to miss it.
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