Why You Should Obsess Over Email Subject Lines
Without an irresistible subject line, your perfectly crafted email will never see the light of day. No opens means no clicks — and no clicks means no revenue.
In today’s privacy-first world, creating engaging email subject lines is even more important. And with tools like Klaviyo, Mailchimp, or Zoho, you have the power to test and optimise at scale.
Ready to turn subject lines into your email marketing superpower? Let’s get into it.
How Apple’s Privacy Changes Impact Email Subject Line Testing
Since the launch of Apple’s iOS 15 privacy features, more than half of all email opens might be inflated due to Mail Privacy Protection (MPP).
Pro Tip: In Klaviyo, use the “Apple Privacy Open” property to filter real opens from MPP-triggered opens. Always A/B test your email subject lines against true opens to get accurate results.
While open rates have changed, what hasn’t is the importance of creating compelling, curiosity-driven subject lines.
8 Best Practices for Writing High-Performing Email Subject Lines
1. Personalisation Drives Attention
- Use first names, past purchases, or quiz results.
- Dynamic variables like {{ first_name|default:’there’ }} in Klaviyo make this easy.
- Go beyond the basics: Mention products they browsed or abandoned.
Example: “[First Name], forgot something? Your [Product] is still waiting!”
2. Keep It Short and Mobile-Friendly
- Most emails are opened on mobile. Think 6–8 words max.
- Short subject lines around 7 words have a 30%+ higher open rate.
Example: “Big news inside 📢”
3. Pair with Compelling Preview Text
- Preview text should extend the story.
- Address a pain point or hint at a solution.
Example: Subject: “Struggling with dry skin?” Preview: “Discover your perfect skincare match today.”
4. Use Urgency and Scarcity Wisely
- “Last chance,” “Ending soon,” and “Only a few left” can drive fast action.
- Test carefully — too much urgency can hurt deliverability for low-intent audiences.
Example: “Final hours: 20% off ends tonight!”
5. Always Consider Context
- Think about the inbox clutter your readers face.
- Context-based triggers (recent browse, cart abandon) should guide your messaging.
Example: “Still thinking about our bestseller?”
6. Master the Curiosity Gap
- Hint at what’s inside without giving it all away.
- Spark questions they can only answer by opening the email.
Example: “You’re not going to believe this new drop…”
7. Emojis: Sprinkle, Don’t Flood
- 1 emoji max.
- Ensure it enhances meaning, not replaces words.
- Preview across devices; not all emojis render the same.
Example: “New season essentials 👟 Are you ready?”
8. Leverage AI for Scale and Insights
- Use AI tools in Klaviyo to generate multiple subject lines.
- Let the platform learn from past performance to improve future open rates.
Real-World Email Subject Line Examples That Work
- Supply: “This email is better than 👇” — playful use of emojis.
- Dagne Dover: “To you, from you” — short and direct.
- Beekman 1802: “LAST CALL 📣 Free Mini Milk Drops” — urgency + freebie.
- Dossier: “✨Something NEW is coming…✨” — classic curiosity gap.
- Wildfang: “Did I just get ghosted?” — witty browse abandonment recovery.
Next Steps: Test Your Email Subject Lines Like a Pro
A/B test these variables to optimise your results:
- First name personalisation vs. product mention.
- Word count variations.
- Urgency vs. softer storytelling.
- Emoji use vs. no emoji.
- AI-generated subject lines vs. manually crafted ones.
Conclusion: Your Secret Weapon for Higher Open Rates
Great email subject lines are not just creative—they’re strategic. Backed by smart testing, personalisation, and context-aware writing, your subject lines can be the gateway to significantly higher engagement and revenue.
With platforms like Klaviyo, Zoho, and Mailchimp, and CRM tools that unify your customer data, personalisation at scale is easier than ever.
Ready to craft subject lines that your customers can’t resist opening?
📢 Book your free Klaviyo Subject Line Audit and let’s unlock your brand’s full email potential today!
