How to create email subject lines that increase open rates

The subject line is the first thing guests see. Make it short, relevant and worth opening.

Email is the one channel where no algorithm stands between you and your guest. The message lands in the inbox; the subject line decides whether it gets read.

That is worth real money. HubSpot puts the return at $38 for every $1 spent on email marketing. None of it arrives if the email stays unopened, and typing a few words and hoping for the best is how good campaigns die. The content goes straight to your customers, so it has to be right.

Why subject lines matter

When writing a campaign it is easy to put all the focus on the email itself and treat the subject line as an afterthought. In reality it is the first thing people see, and it decides whether they open, ignore, delete, or worst of all send you to spam and never see your messages again. Think of the subject line as the headline and the email as the story: a headline that oversells burns trust, and one that fits earns the open.

Subject lines are also an important form of lead generation. People who actively open and engage with your emails are more likely to buy. If your lines are dull, too long, irrelevant, or interchangeable with every other marketing email in the inbox, your open and response rates will stay flat.

Keep it relevant

A subject line needs to grab the reader and offer some incentive or intrigue, but it also has to match what they signed up for. If people joined your restaurant mailing list to hear about news and discounts, an email headed 'The easiest way to cook pasta' will leave them perplexed.

Do not rehash the same old lines forever either. Regulars notice, and repetition goes stale quickly if you email often. Look at what has converted best in the past, stay close to your winning formula, and A/B test variations to find what your list responds to. Test one variable at a time, like the offer or the first three words, and send each version to comparable slices of your list so the result actually means something.

Get to the point

People scan an inbox the way they scan a supermarket aisle: one glance, instant decision. Keep the line to around five words or fewer, say what you are offering or ask one question, and use as few words as possible.

For a Valentine's deal, 'Amazing deals you won't want to miss this Valentine's Day at insert restaurant name' can become 'Insert restaurant name: Valentine's offers'. Then try variations, because there is no one-fit-all approach. Use verbs and concrete words that create curiosity, and avoid ALL CAPS and strings of exclamation marks.

Some lines that earn the open:

• 'Your table for two is waiting'

• 'Sunday roast, sorted: book by Friday'

• 'We saved you a seat, and a dessert'

• 'Quiz night is back. Fancy it?'

Notice what those lines do: they name the thing on offer, carry a hint of the venue's voice, and fit on one phone screen.

Avoid the spam folder

Dull or irrelevant lines are not the only route to the spam folder. There are other ways to end up there, such as buying email lists to cheat signups. That is a huge GDPR headache, and mailbox providers will associate your sending domain with unwanted mail.

Avoid repetitive salesy language like 'buy now' and 'free'. If your text reads like a robotic sales message, spam filters will treat it as one. Keep image sizes small, ideally below 30kb, link only to reputable sites, and make the email look as genuine as possible to mailbox providers. Send from a consistent domain, warm up new sending addresses slowly, and give people an obvious way to unsubscribe: one spam complaint does more damage than one lost subscriber.

Email marketing is a crowded marketplace, but the technique still works: keep it relevant, keep it short, and give people a reason to open. Treat the subject line like a newspaper headline, and add an exclusive discount or incentive when you have one to give.

None of it works without the addresses in the first place. Stampede captures guest data when people connect to your Wi-Fi, book a table or join your loyalty scheme, and keeps it GDPR compliant, so you always know who you are writing to. Automated campaigns and one-off sends live in the same place, next to the guest profiles they are built from.

Want a hand with your next campaign? Get in touch, or see what email and SMS marketing does in Stampede.