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HomeA subject line is your greeting - it’s the first interaction that your email will make with customers, so ensuring you follow best practice and craft subject lines that get your campaign opened is of paramount importance.
A strong subject line might be one of the single most important differences between someone opening your email, or scrolling straight past.
In fact, 47% of email recipients will open an email based on the subject line alone.
A subject line is a small text section that is shown in various places on your email, mainly in the email preview within the inbox as well as within any notifications sent to the user device.
Aside from your brand name, this is usually the only section of the email that a user will see without opening your campaign.
Your subject should be a short summary of the core message of your campaign. This needs to be punchy, engaging and designed to attract your customers' attention.
This does not leave much room to include longer messages, so you’ll need to experiment with shortening your statements to ensure your subject line isn’t cut off when it’s in the inbox. The recommended approach is to put your key message at the beginning of the subject line in the first 30 characters.
Personalisation is one of the best ways to increase email engagement. So much so, that an Experian Study found emails with personalised subject lines saw a 37% increase in opens when compared to non-personalised subject lines. [1]
Personalisation can be as simple as adding a customer’s first name or order number into your subject line, or as complex as tailoring your emails to reference recently browsed or purchased products.
These are added via dynamic variables, which let you leverage any customer data point you hold. Read more about how to personalise a subject line in Salesfire here.
Some examples of personalised vs non-personalised email subject lines are below:
Good vs Bad:
If your email is offering a benefit to your customers, lay this out within your email subject line. Let customers know what they should expect to receive from your email, and engage them from the start.
You need to understand what your customer wants from your brand, and to provide this for them within the constraints of the subject line.
Good vs Bad:
You can play on a customer's desire for a good deal or to not miss out on a great product by driving urgency in your subject lines. This can be as simple as letting customers know an exclusive sale is about to end, or that a product is low in stock and selling fast.
This engages customers who don’t want to miss out on what you’re offering at the time.
A good way to drive attention to this is through limited usage of action-based words and/or all-caps words, such as:
The trick is to use this sparingly - too much, and you can look spammy. You can actually trigger spam filters by using too many spam-words or too many caps, so make sure you follow the principle of less-is-more.
Good vs Bad
If you want to drive intrigue and engage your customers’ natural tendencies to investigate, use teaser-style subject lines to encourage customers to open your email to find out what’s inside.
These work best for new product launches, collections or for promoting campaigns that haven’t launched yet. This is all about creating interest and bringing users with you on the launch journey.
Vague topics, or asking questions, are a great way to activate a customer’s curiosity - get the customers questioning what you’re offering, and answer this with your email content.
It is important to note that using extreme punctuation like ‘???’ or ‘!!!’ can be marked as spam and that they should not be used often in the same subject line.
Good vs Bad
Everyone reacts differently to content - a young, B2C audience will react to quick, punchy, emoji-using subject lines - but try this with a corporate B2B client, and you’ll look unprofessional and ruin your first impression.
Consider the context of what you’re sending and who you're sending to - ask yourself;
Good vs Bad
Good (B2C): “Trending now: Must-have furniture for spring”
Good (B2B): “5 email marketing mistakes you must avoid”
Bad (B2C): “We have new products” (Too generic, not engaging)
Bad (B2B): “Email marketing tips” (Too broad and unprofessional)
Emojis are a great way to add context and a fun look to your subject lines - but too many can look spammy.
Tips:
Good vs Bad
Good: “Big news: Our biggest sale of the year is here 🛍️”
Good: “✨New arrivals just landed – shop now ✨”
Bad: “HUGE SALE – don’t miss this!🤩🤩🤩🤩” (Excessive caps, looks spammy)
Bad: “🤩🤩🤩Massive savings inside – must open now!🤑🤑🤑” (Too aggressive)
There’s no one-size-fits-all approach to subject lines, and what works for another business might not work for you. The only way to know for sure is to trial different subject lines on your campaigns, so take the plunge and plan a few different styles.
Monitor your open rates.he campaigns with the highest open rates will be the ones with subject lines that have resonated best with your customer base.
We recommend researching what other brands in your space are doing too - sign up for competitors' newsletters, and use this to build up a picture of the standards in your industry. This can then be used to guide your subject line strategy and give you an idea of what your customers are likely expecting.
Be upfront and honest in your subject line. Overpromising and underdelivering will only lead to disappointed customers.
At best, this drives down your engagement rates and drives high unsubscribe rates, and at worst, customers will flag you for spam causing irreversible damage to your sending reputation.
The key is to manage expectations and ensure you can deliver what you’re promising to customers.
Although not directly linked to the subject line itself, timing your email right is essential. You can have the best subject line strategy in the world - but if your email is landing in the customer’s inbox at 3am, it’ll all go to waste.
Look at peak times for when your customers are shopping and browsing on-site, and make sure you send your campaigns during these times.
This applies to sequences and automated emails too - use the quiet hours feature to make sure you’re not sending automated emails outside of your peak times.
Your preview sits alongside your subject line. Make sure this is relevant, and not left blank.
If you leave this blank, it’ll start showcasing the email content - thats your images, header links and HTML code. Use this to support and enhance the core message of your subject line.
This is particularly important for mobile devices, as the character count display view is more limited and varies between mail providers.
55% of emails are opened on mobile devices [3]. With most mobile email clients, you will probably only have five or six words before your subject line cuts off.
Creating the perfect email subject line is a mixture of personalisation, clarity and playing on the emotions of urgency and curiosity whilst keeping your audience's needs in mind.
By testing different approaches, using emojis sparingly but effectively, and ensuring honesty throughout, you can boost open rates and build trust with your customers.
Ultimately, the best subject lines align with your brand’s voice and provide genuine value, encouraging customers to open, engage and convert.
Test, refine, and optimise - your winning subject line is waiting to be discovered!
References:
[1] https://www.zippia.com/advice/email-subject-line-statistics/
[2] https://www.experianplc.com/newsroom/press-releases/2014/experian-marketing-services-study-finds-personalized-emails-generate-six
[3] https://www.cyberimpact.com/en/essential-email-marketing-statistics/
