email-subject-line-optimizer
npx machina-cli add skill nicepkg/ai-workflow/email-subject-line-optimizer --openclawEmail Subject Line Optimizer
A/B test subject line variations using proven copywriting frameworks. Predict open rates based on historical performance.
Instructions
You are an expert at email marketing and copywriting. Create high-performing subject lines, predict open rates, and provide A/B testing recommendations.
Output Format
# Email Subject Line Optimizer Output
**Generated**: {timestamp}
---
## Results
[Your formatted output here]
---
## Recommendations
[Actionable next steps]
Best Practices
- Be Specific: Focus on concrete, actionable outputs
- Use Templates: Provide copy-paste ready formats
- Include Examples: Show real-world usage
- Add Context: Explain why recommendations matter
- Stay Current: Use latest best practices for marketing
Common Use Cases
Trigger Phrases:
- "Help me with [use case]"
- "Generate [output type]"
- "Create [deliverable]"
Example Request:
"[Sample user request here]"
Response Approach:
- Understand user's context and goals
- Generate comprehensive output
- Provide actionable recommendations
- Include examples and templates
- Suggest next steps
Remember: Focus on delivering value quickly and clearly!
Source
git clone https://github.com/nicepkg/ai-workflow/blob/main/workflows/content-creator-workflow/.claude/skills/email-subject-line-optimizer/SKILL.mdView on GitHub Overview
Email Subject Line Optimizer helps craft high-performing subject lines by running A/B tests and predicting open rates from historical performance. It combines proven copywriting frameworks with data-driven insights to guide you from generation to winner selection.
How This Skill Works
The tool generates multiple subject variants using frameworks like AIDA, PAS, and FAB, then runs controlled A/B tests to compare performance. It uses historical open-rate data to forecast outcomes and outputs winning variants, expected lifts, and ready-to-send templates.
When to Use It
- When you want to compare framing (curiosity, urgency, or value) to see which yields higher opens
- When sending time-based campaigns and you need data-driven guidance on the best variant
- When you have historical data and want to predict open rates for new subject ideas
- When launching new offers, updates, or features and need compelling hooks
- When testing audience segments with tailored subject lines to maximize engagement
Quick Start
- Step 1: Define campaign goal, audience, and winning criteria.
- Step 2: Generate 3–5 subject variants using AIDA, PAS, or FAB templates.
- Step 3: Run an A/B test, review predicted open rates, and deploy the winner.
Best Practices
- Test 3–5 subject line variants per campaign to isolate effects
- Pair subject lines with corresponding email content to reduce mismatch
- Predefine success metrics (open rate, sample size) before testing
- Use established frameworks (AIDA, PAS, FAB) to structure hooks
- Schedule tests to avoid confounding factors (same day of week, same send time)
Example Use Cases
- Example 1: Curiosity vs clarity — test 'Unlock your personalized insights' vs 'Your personalized insights are ready'
- Example 2: Urgency vs value — test 'Ends tonight: save 25%' vs 'Your exclusive 25% off ends tonight'
- Example 3: Problem-solution — test 'Struggling with inbox overload? Here’s a fix'
- Example 4: Benefit-highlight — test 'Boost your open rate by 12% with this subject'
- Example 5: Offer-focused — test 'New feature release: see what’s new for you'
