10 Ways to Write Engaging Email Subject Lines Based on 28 Case Studies

Author's avatar Content Marketing Jul 18, 2018 17 minutes read

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    Peter Caputa

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    It’s an obvious fact: if your subject line doesn’t capture people’s interest, your email won’t get read.

    If you’re responsible for writing subject lines, you’re under a lot of pressure to create engaging snippets that result in opens. So what do you do when you’re staring at a screen, trying (and failing) to come up with something clever?

    We polled marketers to find out what subject lines have generated high engagement rates for them. Then we asked what strategies they used to create those subject lines.

    While there’s no one right way to write a subject line, you can use these ideas as a swipe file when you’re stuck and in need of some quick inspiration to help you write something that will boost your open rate.

    Editor’s note: Want to track the performance of your email marketing campaigns in real time? Download our free templates that display your email traffic overview (for those using Google Analytics) and your email campaign results (for those using HubSpot).


    Is there an average email open rate?

    If your open rates aren’t great, don’t get down on yourself. We polled marketers on their average email open rate and found that 40% of them see open rates between 20%-30%.

    Only 20% of marketers reported an average open rate of 50% or higher. [Tweet this stat.]

    Here’s what we can learn from those top-performing marketers.

    1. Use Curiosity

    It’s human nature to want to know what your successful peers are doing. (Hence why Instagram exists!) IsabelDelmás with Ondho tells us that she achieved a 23.1% open rate with the subject line “Great Branding Examples.” She says, “The digital marketing industry is always looking to improve and constantly benchmarking the actions and campaigns of the competitors. So this was a subject line whose chances of performing well was very high.”

    Adam Rowles of Inbound Marketing Agency shares how to boost the performance of the classic “Quick Question” subject line to generate an open rate of over 60%. He says, “There have been studies that have suggested this subject line has ~35% open rate. However, it works in my experiments with higher engagement. I use plain HTML emails, which makes the emails look more personal. I recommend keeping these emails short.”

    Kevin Adkins with Kenmore Law Group uses the subject line “Why?” to generate curiosity and a 65% open rate. He says, “I think this has been effective because the question gets people curious. It targets people of all states of mind. If the person is happy, depressed, paranoid, angry, relaxed, or anxious, they will be curious about what “why?” is asking.”

    Dario Sipos with DWR says, “The best performing subject line we used is ‘Four Critical Questions Every Business Must Answer,’ with the open rate of 19%. This subject line works well because it combines valuable advice which can be applied to any business owner while targeting a broader audience. People like to read numbers in headlines combined with powerful advice.”

    Kevin George with EmailMonks achieved a 50.3% open rate with “Hey [First Name]! Which one of these would be your favorite read?” He says, “Since the subject line was intended to seek their opinion on which article is their favorite, it increased their curiosity to open the email to know more about the articles. Curiosity always works. This isn’t something new. But it does prove that to get good open rates, subject lines should be persuasive enough to get the subscriber to click on it.”

    2. Personalize and Customize

    According to research by Campaign Monitor, emails with personalized subject lines are 26% more likely to be opened. Gerry Dapergolas with Strategic Internet Consulting shares that the subject line, “[First Name], take a look at our February favorites ✈??” achieved a 45% open rate. She says, “Firstly, we used a personalization token for the recipient’s first name. This may have made users more inclined to open the email because it was personally addressed to them, with their own name clearly showing in their inbox.”

    David Denning with Jumpanzee says that his subject line “A Special Offer for Existing Jumpanzee Clients” had a 50% open rate (and the company ended up converting 30% into sales!). He shares, “It works because it’s ‘special’ for them, and they are familiar with us. I think any subject line that is short, to the point, and targeted for your audience will perform well.”

    Nicolai Froehlich says that customization is key. His subject line “June 2018 — HaTikva Project helps you smile” worked well “since it was sent to a targeted audience about a specific organization that can help with a specific need or service.”

    Tammy Duggan-Herd with Campaign Creators uses personalization even on premium content delivery emails. She says that her subject line “[First Name] — Your How to Create a Lead Nurturing Campaign guide is here” achieved a 90.91% open rate. She explains, “What made this subject line perform so much better than others I’ve used before? Personalization. The psychology behind it is simple: Everyone wants to be treated as an individual. By including their name within the subject line, the message becomes more intimate and feels like its coming from a real person — in turn, building trust.”

    Nicole Sengers with Spitfire Inbound saw a 70.5% open rate with her subject line “Be the first to find out more about the new Suzuki Swift??” She explains why: “This email was a sneak peek at the latest car being launched. We sent it to people who previously enquired about the Swift (hyper-targeted). I also feel it did well because people love to be in the know and be first!”

    Jessica Dais with TakeLessons Live says that her subject line “Hi [First Name], Quick question.” generates a 24% open rate. She says, “We used this subject line in a recent promotional campaign, and I think it worked for a couple different reasons. 1) It’s personalized. 2) It sounds casual and conversational. Because it doesn’t use all caps or a million exclamation points, it stands out from other promotional emails and spam. 3) The use of the word ‘quick’ provides even more incentive to open it — because everyone is busy, especially when sifting through loads of new emails! Keep it simple and give the recipient a compelling reason to see what’s on the other side.”

    Camille Carlton with Smartleaf shares, “Our best performing subject line is: ‘Nice to meet you, [First Name].’ To provide some context, the recipients of this first email have never received email marketing communications from us. They have, however, been connected with us on LinkedIn and therefore warmed by our sales team. Some recipients may have had a very short back and forth on LinkedIn, but there’s been no formal introduction. This email serves to do just that, in addition to providing an introduction to our company and product. Then what explains this subject line’s open rate success of 50%? It’s friendly and tackles personalization in a natural way. As humans, we love reading and hearing our names. It’s no different in an email.”

    3. Generate Urgency

    Gerry also says that she believes making the subject line time-specific led to a higher open rate. “We sent out the email in February, which added a time pressure element to the campaign by implying that these holiday deals would only be available in February.

    Avi Cohen with Pacific54 achieved an open rate of 45.65% with the subject line “We Need Your Help! Get $5 in Free Gas For Completing Our Survey.” The reason why: “We believe this performed as well as it did because of three things: the word “free,” urgency, and instant gratification. In this case, the subscribers already know the company offers fuel delivery — but this campaign is adding something new (and free!). This email subject line is also a classic example of urgency. If the subscriber is already interested in what the company offers, they might open the email on that alone. Another important thing to note about this specific email campaign is that the free gas is guaranteed, they only need to complete the survey. This isn’t a contest or a drawing. If you complete this, you’ll get this for free: it’s a very simple message, and in this case, it was effective.”

    4. Experiment With Emojis

    Another insight shared by Gerry with Strategic Internet Consulting is that emojis can impact open rates. She says, “We had previously conducted some research on our target audience and found that adding emojis to our subject lines increased open rates by 20%.” After this discovery, the company began adding emojis to all campaigns sent to this audience segment. Gerry adds, “We have learned that the best way to select a winning subject line is to A/B test two variations to a small sample of the recipient database. We sent two variations to 10% of our recipients and waited 24 hours to see the results. We then sent the winning subject line (based on open rates) to the remaining recipients in the database, which gave us the final result of the 45% open rate.”

    Laurel Mintz with Elevate my Brand uses emojis successfully as well. She shares that she used the cat emoji with the heart eyes along with her subject line “Valentine’s Squishmallows Are Now Available!” to achieve a 39% open rate (compared to the retail industry average of 9.6%). She says, “We have noticed that for this particular brand, emojis within the subject line do very well for open rates.”

    5. Be Clear on Benefits

    A recipient wants confidence that time spent opening and reading your email will be worth it. The clearer you can be about your email’s value proposition, the better. MaryAnn Pfeiffer with 108 Degrees Digital Marketing shares that her subject line of “[Product Type] Coupon #1” landed a 76% open rate. She explains why: “This is a new subscriber automation, and it’s the first offer a subscriber receives after signing up for our email list. Our other email campaigns for this client use much more intricate subject lines with specific calls to action, but in this case, we went straight for the jugular. We know the site visitor signed up for coupons and discounts, so we call it what it is. This email has been running for several years, and is holding consistent at this open rate.”

    Tori Bartolozzi with Kiwi Creative also achieved an exceptional open rate (60%) by being straightforward. She shares why she thinks her subject line of “Key Takeaways from SaaS Connect 2018” generated such a strong response: “With information overload on the internet these days, people want a quick rundown of highlights. As marketers, we sometimes overthink things when a straightforward and transparent subject line may do the trick.”

    Jonathan Aufray with Growth Hackers says that his subject line template “[First Name], here’s how you can [Benefit from our Solution]” always achieves high open rates. “By writing the first name of the recipient in the subject line, the email looks personalized, and this increases opening rate. Then, showing the main benefit the recipient will get from opening the email is very effective.”

    AJ Alonzo with demandDrive uses a simple template to achieve high open rates: “[Pain Point] | [Your Company Name].” He says, “Obviously, it’s going to change based on who you’re reaching out to, but laying out a major pain point followed by your company name is the general premise of this subject line. It’s short and right to the point: We know you have this pain point (or companies like yours generally have it), and our company can help. Subject lines should do a good job of summarizing what you want to talk about, and in this case, it’s pretty clear. Are you having this pain point? We can help.”

    Darren Schreher with Into the AM shares that his subject line “$20 Hoodies & Free Shipping – 24 Hours Only” was successful. “This subject line worked tremendously well for us for several reasons. First, our hoodies are usually in the $60 price range, so knocking $40 off is a pretty big deal. Second, we know how much people hate paying for shipping. It can sometimes be the deciding factor between something making a purchase and abandoning their shopping cart. Third, this is a time-sensitive offer. It means the customer has to act quickly, or they’re going to miss out. This is one of our favorite styles of subject lines because they get the customers attention and often times lead to a flurry of sales.”

    6. Be Concrete

    Abstract concepts can be difficult for recipients to process. If someone has to stop and think about what your subject line means, your email will get passed over. Rick Ramos with HealthJoy.com shares that, “Our best-performing subject line came from an article that Entrepreneur wrote on us. Our product is fairly robust and services the healthcare industry. In essence, we simplify the healthcare experience for employees and save companies a ton of money in the process. Entrepreneur called us ‘Siri of Healthcare,’ and I thought it captured our message in the simplest way: Introduction to the ‘Siri of Healthcare.’ We’ve gotten open rates around 25-35% with this subject line. Once they open it up, it also helps that we got social proof from a publication like Entrepreneur and got a great click rate as well.”

    Richard Duvall with Rough Country shares that his subject line “Thank You For Updating Your Garage” receives a 68.2% open rate. He says, “Our customers really enjoy direct communication and acknowledgment. Interaction with any form of acknowledgment is high across all our channels.”

    7. Try Using the Word “News” or “New”

    Chris Byrne with Sensorpro sees a 68% average open rate with the subject line “We have news about your account.” He says, “Subscribers that have an account typically have a higher open rate as they have a stronger connection, so it’s not much of a surprise. From a psychology perspective, I think the account issue, the brand, and the word ‘news’ are factors here. As an aside, I have an Alexa and notice they use ‘What’s new with Alexa?’ I think that’s a clever subject line using the word ‘new.'”

    8. Get Real

    James Pollard with The Advisor Coach shares, “The best performing subject line that I’ve ever used has been ‘Did I Piss You Off?’. I send this to people who haven’t opened the last twenty emails I sent as a last-ditch effort to get them re-engaged. If they open this email and interact with it, I add them to another campaign to try and bring them back to the fold. I think this subject line works so well because it jars people and gets their attention. People who didn’t bother opening the last twenty emails ended up opening that one in droves.”

    9. Use FOMO (Fear of Missing Out) or Loss Aversion

    Shannon Howard with Overit Media says, “The best performing subject line I’ve ever used was, ‘Doors re-opening for 24 hours.’ The open rate was around 30%, but I’m basing performance off of sales, not just open rates. Here’s the psychology behind it: In this industry (health education), consumers are not motivated by the usual early bird stuff (bonuses, discounts, etc.). They’re motivated by the fear of missing out. They don’t want the doors to close on something, then realize that they really should’ve hopped in while they got the chance. For this email, I saw sales nearly triple within 24 hours. This doesn’t work for every market. I think it’s important to know whatever industry you’re in and what motivates them, which you can discover by doing some market research and testing different subject lines and CTAs.”

    Craig Andrews with allies4me gets an 18.1% open rate on “You’ve been unsubscribed.” He says, “This may seem unremarkable until you realize we only send that to people who haven’t opened a single email in 6 months. Even though the click rate is 5.6%, we actually reactivate about 2% of the list. Many marketers are happy when they get a 2% click rate on an active list. We’re able to beat that with a dead list.” Craig shares that there are three primary psychological elements to this campaign:
    • Scarcity and loss aversion: “They are told they’re about to be cut out of future updates. We use opt-in lists, so they found our content valuable at some point. They avoid losing future value.”
    • Autonomy: “Many unsubscribes and spam reports are about the reassertion of control. Our script blatantly says they are in control. The goal is to reaffirm their autonomy so they don’t feel the need to assert it by unsubscribing.”
    • Consistency: “When they opt back in, they invoke consistency which increases their engagement in future campaigns.”

    You can read the entire email script and strategy here.

    PRO TIP: Before you can track subject line performance, you’ll need to have an email campaign set up in your email marketing platform. Make sure that you have multiple versions of your email with different subject lines to test. Once you’ve sent your emails, monitor the performance of each subject line in marketing reporting software. Compare the metrics for each version of the email to see which subject line performed best.

    10. Ask for Help

    Dan Vanrenen with Taskeater shares that his subject line “[First Name], can you help?” has been successful. He says, “Sending hundreds of B2B email campaigns for ourselves and our clients each month, it is our aim is to be both personal and direct in our email copy. We have found the most successful B2B campaigns cut straight to the chase, present a clear and simple offering, and most importantly, remain human. This subject line immediately personalizes the email by naming the recipient, but also fundamentally changes the approach from a sales email to a request for help. On a psychological level, that is the shift from defensive, expecting a pitch, to cooperative, helping with a request.”

    Andrea Velazquez with Bonafide‘s subject line of “Can I get your feedback?” received at 57% open rate. She shares, “This subject line made it seem like the email was a personal request from someone in particular rather than a general mass email request. The winning subject line also requests a specific action. Make it look like it’s an email that they would receive from a colleague. Simple, casual, and specific.” Learn more about how Bonafide uses email marketing here.


    Subject lines can make or break an email campaign. And while the pressure may be strong, you’ll be more than up for the challenge with this collection of ideas. We’d love to hear what you’ve learned from high-performing campaigns. Share with us in the comments. Measure the success of your email subject line based on insight from your email marketing dashboard.

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    Article by
    Laura MacPherson

    Laura MacPherson is a freelance copywriter who helps tech and software companies engage their audiences and communicate their unique value. She's a nerd who loves learning, but she balances her bookishness with a hiking addiction.

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