How to write the best subject lines in 2019

On average, North Americans receive 121 emails per day, and click through 3.1 percent of them.

The rest are swept away into an infinite sea of ignored digital content, or worse, deleted.

Meanwhile you’ve put in countless hours to formulate the kind of products and services your clients will love. You’ve crafted emails to exude the tone and style of your brand. You’ve curated a website to feel like a second home for fans of the things only you can offer.

All this hard work can boost conversions or go to waste simply because of a small assortment of words—the subject line.

Fortunately for businesses and consumers alike, expert marketers have had several years to figure out what sets apart a good subject line from those that clients scroll past.

Here are 8 tools and techniques that continue to hold up in the industry.


If you are well acquainted with the tastes and preferences of your clientele, you already possess a key ingredient to writing effective subject lines.

Click through rates increase by 17 percent when subject lines are personalized. Conversion rates increase by 10 percent.

Use your client’s names when you write to them, but do not stop there. Track their purchases or interactions with your business and use that to follow up or tell them about a similar product they might like.

Maybe it’s been years since they last visited your business. Use that too. Start off a subject line with “We miss you,” or “The last time we saw each other…”

Take this as an opportunity to tell your client you have noticed their absence. Make them feel important.

Segmenting your client list according to shopping patterns, interests and demographic provides a clear path to personalized messages.

Marketers who have employed segmented campaigns reported a 760 percent increase in revenue this year.

Remember, nobody likes to receive an email that makes them feel like they’re but one on a list of millions.

Keep it Short

Data has shown that subject lines of no more than 7 words or 41 characters in length lead to the highest open and click-through rates. Some marketers would suggest going with even shorter lines at 25 to 30 characters.

When determining the length of your subject line, it is important to consider what sort of devices your clients are using to read their messages.

What displays beautifully on an iPad or desktop might not look so great on a mobile screen.

An average of 60 percent of emails are opened through mobile devices, and this number is expected to grow each year.

The biggest complaint about viewing content on these tiny screens is inapt formatting.

Statistically, it only takes about 3 seconds for most consumers to decide they’re fed up with a distorted display and proceed with deleting an email. Some go as far as unsubscribing altogether for this reason alone.

As you may have already guessed, the most preferred mobile technology is the Apple iPhone. On these devices a maximum of 41 characters display correctly in portrait format and 64 characters in landscape.

The second most popular browser is Gmail which allows for an ideal length of 70 characters.

Shorter subject lines also mean your emails are less likely to get caught in a spam filter and more likely to be delivered.

Find the Right Language

In addition to being brief, a good subject line will inspire the reader to learn what’s inside your email.

Beginning your lines with verbs will likely provoke your readers to act.

The words you choose should make it easy for your clients to foresee themselves benefitting from your product.

For example, if you want to offer your clients an exclusive experience to an event, something like, “Sip martinis with the cast of Hustlers,” engages the imagination more than, “Discounted ticket offer for this TIFF event.”

Another good technique for inducing action is to write for the basic human senses.

Suppose you’re running an organic skincare line and it’s the middle of a dry, bone-chilling winter. You want to put out your new assortment of bath salts.

Write up something like, “Sink into a steamy, hot vanilla bath,” to get your audience halfway to your product.


Marketing experts recommend using subject lines that create a sense of urgency or denote scarcity in product quantities. The idea is that consumers will want to open emails out of fear of missing a good deal.

In order to keep its potency, FOMO (fear of missing out) is best used in moderation. Here’s an example of what can happen when it is used too often.

A 3-hour flash sale of 60 to 80 percent off an entire clothing store may sound like an exciting opportunity on its own, but how do you think consumers might feel if they received this message on an almost weekly basis?

Not only does the urgency fade, but over time the business begins to appear desperate and depreciated.

Also, who will ever want to pay full price for an item knowing that a sale is right around the corner?

Use Emojis

If you have an emoji that would fit perfectly with your subject line, don’t be afraid to use it.

Not only will it make your message stand out from a page full of text, one of these little guys could pick up open rates by 56 percent.

First consider how the people in your industry might perceive such a message. Will they love it or is there a chance they might find it inappropriate?

If you don’t already know, the best way to find out is to put these emojis to the test. Send out one set of emails without the emojis to one group of clients and emails containing them to the other group. You can make your decision based on how your readers respond.

When you do incorporate them into your subject lines, make sure they are relevant and that you keep it to one emoji per line. Too many will look cluttered and may confuse your message.

Pique Curiosity

Your subject line can tell readers what to expect from opening your email without giving everything away.

Tease them and convince them that they will not be satisfied until they open your message to get the full scoop.

Of course, there are many ways to do this.

Suppose your email contains an insightful story that could help others in your industry learn from your mistakes.

A subject line that reads, “What my bad-boss reputation costed me,” could spark curiosity in your audience because not only do they want the rest of the story, they also want to avoid falling into the same pit.


Feelings drive 80 percent of sales.

Subject lines that harness emotions -good or bad – are more likely to increase conversions than those that don’t. These are also excellent opportunities to build a connection with your readers.

Use your knowledge about their interests and the things they care about to capture their attention with something that will move them instantly.

A subject line that reads, “Doing My Happy Dance at 92,” may inspire feelings of joy or delight and curiosity to find out more about this person. Click.

Negative sentiments can also have the same effect.

The following subject line was written by Medium blogger Jessica Wildfire. She plays on an emotion that anyone who has ever tried to achieve anything may experience at varying degrees.

10 Signs You’ve Got a Stupid Idea,” is the title of her latest post for The Startup. 

Someone may come across this and immediately wonder whether they’ve got a blind spot they’re going to find out about in a second. Click.

Who doesn’t want to be spared the pain that comes with watching a dream unfold into an utter failure?

Web Tools

You can test your subject lines before sending them out to your clients for better results.

Crafting the right phrase, figuring out what combination of techniques is suitable for your audience takes time you might not always have.

Wired Messenger has compiled industry trends and statistics to make them all accessible through one easy tool. can help you make the most of your email marketing campaigns.

The site will give you an overall score for your subject line to indicate how well it may perform.

It will also provide a breakdown of what you did right and what you could do better based on approaches that are known to drive the best results.

It’s free, and if you’d like to learn more, you can always contact the folks at Wired Messenger.

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