Email subject lines for ecommerce: 44 examples and what makes them work

What makes a subject line get opened#

People decide whether to open in a second or two, and they decide from three things together: who it is from, the subject line and the preview text. The subject line cannot carry everything, so give it one job: tell the reader what is inside and why it matters to them.

• Clarity over cleverness. “20% off knitwear until Sunday” beats a pun that needs the email to make sense.
• Specific beats general. Name the product, the color, the amount or the date. “The wool overshirt is back in size M” tells a waiting customer everything.
• One idea per subject. If you need “and” twice, the email is probably doing too much.
• Honest. The email must deliver what the subject promises. In the US, CAN-SPAM prohibits deceptive subject lines ^S3, and Gmail asks senders not to start subjects with Re: or Fwd: unless the message really is a reply or forward ^S1.

Pair the subject with preview text

The preview text is the line most inboxes show next to or under the subject. If you leave it empty, the inbox fills it with the opening words of the email, which are often “View in browser”. Use it to add the second piece of information the subject had no room for.

How long should a subject line be?#

There is no single correct length, because each email app and screen size cuts the subject at a different point, and phones show less than desktop inboxes. What holds everywhere is that the opening words are always visible. Put the product, offer or deadline at the start, and treat anything after the opening few words as a bonus.

• Lead with the noun or the number: “Free shipping this weekend”, not “This weekend only, we are offering free shipping”.
• Cut filler such as “Check out”, “Introducing” and your brand name, which the sender line already shows.
• Read the subject together with the preview text on a phone before you send.

The free subject line checker shows how a subject and preview text look in an inbox and flags capitals, repeated punctuation and misleading prefixes.

44 subject line examples by campaign type#

These are written for Ninefold, a fictional small apparel brand selling knitwear, outerwear and basics. Swap in your own products, numbers and dates.

None of the examples use exclamation marks or emoji. Both are allowed, but they rarely add information, they make every shop’s email look alike, and Gmail asks senders not to use emoji or symbols to imitate graphic elements ^S1. A specific subject does the work on its own.

New arrivals and product launches

• The autumn knitwear is here
• New: a waxed jacket made for wet commutes
• Five new colors in the merino crewneck
• Just in: the heavyweight tee in black and bone

Restocks

• The rib beanie is back in all six colors
• Back in stock: the wool overshirt in size M
• You asked, so we restocked the cardigan
• Restocked: the merino crewneck in oat

Sales and promotions

• 20% off knitwear until Sunday
• Our winter sale starts now: up to 40% off outerwear
• Free shipping on every order this weekend
• Two days of 15% off basics

Black Friday and Cyber Monday

• Black Friday: 25% off everything, no code needed
• Subscribers shop Black Friday from Thursday at 6 pm
• Our Black Friday sale ends Sunday night
• Cyber Monday: last day of 25% off

Holiday and gift campaigns

• Gifts under $50 for everyone on your list
• Order by December 18 for delivery before the holidays
• The gift guide: knitwear, scarves and small things
• Still need a gift? Gift cards arrive by email in minutes

Cart reminders

• Your merino crewneck is still in your cart
• Not sure about the size?
• Questions before you check out?
• Your saved cart, with free shipping until Sunday

After the order

• Your order is on its way, plus how to care for wool
• How to wash merino without shrinking it
• How is the overshirt fitting?
• Thank you for your order: 10% off your next one

Win-back

• It has been a while: here is what is new
• 15% off to welcome you back, until Friday
• Do you still want to hear from us?
• New outerwear since your last order

VIP and loyalty

• For our regulars: the new collection a day ahead
• A thank-you for your fifth order
• Your member price on the winter coat
• A 48-hour private sale for returning customers

Newsletters and stories

• How we make a sweater that lasts ten winters
• Inside the mill that spins our wool
• Three ways to wear the overshirt
• What to pack for a cold weekend away

Last chance

• Last day for 20% off knitwear
• The sale ends at midnight tonight
• Free shipping ends at 11:59 pm
• The winter sale closes tomorrow

Ready-made emails behind several of these are in the templates: new arrival, back in stock, Black Friday sale and last chance. For full cart reminder sequences, see abandoned cart email.

What triggers spam filters, and what is a myth#

Lists of “spam trigger words” are mostly folklore. Mailbox providers judge mail mainly by who sends it and how recipients react. Gmail warns that user spam reports can lower a domain’s reputation over time and that unauthenticated messages may be marked as spam or rejected ^S1. Yahoo describes the same idea: each sending IP and domain has a reputation, and mailing people who do not read your mail or who report it harms that reputation ^S2. Deliverability specialists who test content filtering find that single words rarely decide placement on their own ^S4.

Subject habits that do look like spam to people, and so lead to complaints: all capital letters, stacked punctuation, fake urgency, and subjects that promise something the email does not contain. See why emails go to spam for the full list.

How to test subject lines on a small list#

1. Change one thing at a time: the offer, the product named, or the wording of the same idea.
2. Judge by clicks and orders, not opens. Apple Mail Privacy Protection loads email content in the background whether or not the reader opens it ^S5, so open rates overstate real reading.
3. On a list of a few hundred people, a split test on one send is mostly noise. Compare the same campaign type over several sends instead: three restock emails with a product-led subject against three with a benefit-led one.
4. Keep a short log of each subject, its click-through rate and its revenue per recipient. Patterns show after a month or two.

For which numbers to watch and how to read them, see email marketing metrics.

Writing subject lines in Claude or ChatGPT with Tellnod#

With Tellnod connected, the subject line is part of the same conversation as the rest of the campaign. You can ask for options, pick one, and see it in the preview before anything goes out.

• “Give me five subject lines for the overshirt restock. Name the product and the sizes, no exclamation marks or emoji.”
• “Use the third one, and write preview text that mentions free exchanges.”
• “Send me a test so I can see it in my phone’s inbox.”
• “How did this restock email do compared with the last one?”

The preview card shows the email on desktop and mobile, and the send goes out only after you press Confirm on the approval card. Results come back in the chat with clicks and, once your store is connected, orders, so you can compare subjects across campaigns. Tellnod is free up to 500 contacts and 2,000 emails a month; see pricing or connect it.

FAQ#