Let’s be honest, most subject lines are more wooden than witty, especially in the case of promotional emails. The average opening gambit of these messages is usually too salesy, too irritating or just too damn boring to earn a click.

B2B organisations are often the worst offenders for duller-than-ditchwater openers and to be fair, it’s more difficult to sell a cloud solution datasheet in one line than it is to sell discount Ray-Bans.

Part of the problem is there’s a lot of conflicting, outdated advice out there on how to write effective subject lines and what does exist is typically aimed at the very companies selling sunglasses and other consumer products.

We felt it was about time we shared some of our own tried-and-tested subject line hacks. The advice below is based on research we’ve carried out over the last few months and our first-hand experience sending open rates into orbit on behalf of B2B businesses.

Next time you’re frantically stabbing out a subject line with five minutes to go before distribution, maybe bear some of these tips in mind.


  1. Keep it short... No, shorter than that!

Research suggests 30 – 50 characters is the range all marketers should be aiming for when writing subject lines.

This may seem a like a big ask but it’s worth taking the time to whittle down lengthy first attempts. A 30 – 50 character line wont be cut off by the narrow inbox displays used by some email clients and will fit on most tablet and smartphone screens, significantly increasing the likelihood that it will be read.

  1. Put your best foot forward

The first few words of a subject line are crucial so ensure they grab readers and don’t let go. Active phrases work well here, as do eye-catching words and we’ve seen success placing words in brackets.

Whichever approach your choose, remember that your audience should understand the topic of your email by the time they’ve read the first three words of your subject line.

  1. Get personal

Personalisation is proven to increase open rates but a personal touch should be applied with care. Too little tailoring may render your line irrelevant, too much and you’ll appear intrusive. Striking a balance between the two is a challenge, but when in doubt err on the side of caution.

Opinions vary on the use of first names in subject lines but recent research suggests this does in fact increase open rates. If you’ve divided your audience by persona we also recommend that you use subject lines to speak to the specific needs of each segment.

  1. Consider context

Offering your audience information or solutions based on their location is proven to increase engagement so if you have the data available this is another effective personalisation technique.

Also consider the time that you’re sending your email and check if you can use it to inform the content of your subject line. For example, if you’re sending an email at 5pm you could use the line ‘Something to read on the train home…’

  1. Ask questions

Using questions in subject lines is an old trick but it still has potent magic. An unanswered question either places the answer in the reader’s head or starts their brain whirring to find it. Either way, they spark instant engagement and whet the appetite for the full email to come.

  1. Be a culture vulture

Referencing pop culture through catchphrases, lyrics or quotes can set your subject line apart from staid equivalents littered with buzzwords and business jargon. However, as with using humour and personalisation, tread lightly and make sure the line will connect with your audience before pressing send.

  1. Resist the call of the emoji

Using symbols or emojis to break up copy and catch the eye may be tempting but in the world of B2B this tends to be a bad idea. You risk alienating those who find them irritating and as they may not render on certain email clients you can waste precious characters by using them L.

  1. Use num3rals

Using numerals instead of words when writing numbers can help your subject line stand out. This may go against everything your teachers taught you but there’s method to this grammatical madness. As we’re not used to reading numerals in sentences they naturally draw our eye. What’s more, replacing words with numbers enables you to cut down on the all important character count.

  1. Avoid sales speak

Although words such as ‘free’ and ‘special offer’ have been proven to increase open rates in the past, it’s now best to leave this type of language to B2C businesses. Subject lines containing these words can trigger spam filters but even if they don’t, readers will often ignore them as they associate these words with digital junk mail.

  1. Test, test and test again

Our final point is also our most important. If you’re not certain you’re using the right copy in your subject lines, we strongly recommend A/B testing a few ideas each time you run a campaign. This is the only way to ensure your subject lines are as relevant and engaging as possible.


We could do this all day but we’ve got subject lines and emails to write. However, if you’d like more advice on how to stand out in a cluttered inbox, get in touch at hello@hitfirstbase.com. We’ll respond to those of you with the worst subject lines first.

Equally, if you’ve got your own pearls of subject line wisdom that you’re aching to share, we’d love to nick them. Drop your thoughts in the box below.


Content marketing, Blog, creativity, IP Based Marketing, subject lines

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