No matter how good your email is, nobody reads it if the subject line doesn’t earn the open. It’s the one line you must get right. The good news: a few simple rules and a swipe file of examples will lift your open rate fast.
1. Be specific, not clever. “3 ways to cut your energy bill” beats “A bright idea” every time.
2. Keep it short. Aim for under 50 characters so it doesn’t get cut off on mobile.
3. Create a curiosity gap — honestly. Tease the value, but never bait-and-switch, or you’ll train people to ignore you.
4. Use their language. Write the way your reader talks, not the way your marketing team does.
5. Add urgency only when it’s real. Deadlines work; fake ones destroy trust.
6. Personalise with intent. A first name helps, but a relevant detail (their city, their last purchase) helps more.
7. Avoid spam triggers. ALL CAPS, “FREE!!!”, and rows of emojis hurt deliverability and look like spam.
Curiosity: “The mistake almost everyone makes with [topic]” · “I was wrong about [thing]” · “What nobody tells you about [topic]” · “This took me 10 years to learn” · “Don’t do this”
Benefit: “Save 2 hours a week with this” · “A faster way to [outcome]” · “Your [thing], but easier” · “Get [result] without [pain]” · “The 5-minute fix for [problem]”
Offer: “20% off ends tonight” · “Your [discount] is inside” · “Last chance: [offer]” · “Just for subscribers” · “Doors close Friday”
Welcome: “Welcome — here’s what’s next” · “You’re in. Start here.” · “Your [freebie] is ready” · “Glad you’re here” · “A quick hello from [name]”
Re-engagement: “Did we lose you?” · “Still want these emails?” · “We saved your spot” · “One last thing before you go” · “Here’s what you missed”
Question: “Quick question about [topic]” · “Are you making this mistake?” · “What’s stopping you?” · “Ready for [outcome]?” · “Can I help with [problem]?”
...and the best subject line of all is the one you test against your own list. Swap one word, send to two halves, and let your readers tell you what works.
Examples get you started; data makes you better. BrandBits shows the open rate for every campaign, so you can see which subject lines actually earn the open and write more like them.