Subject Line Strategy

Catching Your Customer’s Eye in 41 Characters or Less

By: Retention Marketing Specialist Dominique DiNardo

Top-selling product? You’ve got it! Amazing graphics? Ready to go! Catchy copy and alluring CTAs? On it! List of customers who are totally engaged with your brand? Locked and loaded!

Your beautifully-crafted email is ready to launch. Now, all you need to do is get your customers to open it. Easy enough, right?

Think again.

With consumers’ inboxes getting flooded with messaging everyday, you need to stand out. There’s an art to achieving high open rates and we’re here to help you master it.

Before we get started, there is something important to keep in mind. There is no one size fits all strategy because (spoiler alert: every email is different).

For example: If you’re running a sale maybe your subject line is: “25% OFF YOUR FAVORITE STYLE. SAVE NOW!”

Or, maybe you’re featuring a new product and want to go with something a little different like: “FirstName, these straight leg jeans were made for you!”

Both of these subject lines should be treated differently. There is no universal template you can follow to ensure high open rates, but there sure are some pillars that will help guide you while you test the strategies that work best for you. Let’s dive in…

Length — Keep It Simple.

The ideal subject line is around 40–45 characters long. Number one goal? Grab your audience’s attention in as few words as possible. In addition, you need to keep it short so that the subject line is seen fully in their inbox. If any important messaging such as SALE or a percentage off trails off the screen and out of the preview, you could lose a potential conversion. Another thing to consider is the mobile-first world we live in today. Be sure your subject lines are short enough so that the mobile consumer is able to understand the purpose of the email before even opening it.

Content — Keep It Clever.

We’ve all seen it before: the punny subject line that grabs your attention immediately. Wordplay and clever copy will always drive open rates up. Whether you’re saying something silly or your audience just appreciates a good play on words, a well-written subject line will always outperform the others. Let’s get into an example:

Say you’re a home decor company geared towards millennials who are either buying their first home or have been renting for a while and due for a refresh. Which do you think would work better?

“It’s time to replace your curtains. No shade.”


“You need to check out these curtains.”

If you said the first — you’re probably right! There are ways to jazz up the second — such as personalizing it with the customer’s first name — however, as it stands now, the first subject line gives your audience a giggle and tempts them to take a look.

Drive Urgency — Keep it Quick.

Flash sales, new inventory, restocks — all great reasons to be pushing urgency in your subject lines. Wording such as “last chance!”, “get it before it’s gone!”, or “ends tonight!” are all indicators that if a customer wants your product or service for a lowered rate or before it runs out of stock, they need to make a purchase as soon as possible. Including these types of phrases in the beginning of your subject line will help your customers understand quickly that there is a sale, new product or restock and now is the time to jump on it.

Formatting — Keep it Consistent.

As silly as it may sound, keeping consistent formatting in a subject line is something that comes up frequently. Now, what do we mean when we say keep it consistent? By no means should yours subject lines be templated — however, there are some key formatting guidelines that should be followed.

  1. If you’re following a title framework — keep every first letter of each word capitalized. For example:

Expires Tonight! Use Your Coupon Now! ✅
Expires Tonight! Use your Coupon now!❌

2. If you’re going to capitalize a word — keep the sentence capitalized. For example:

SALE ENDS TONIGHT! Last Chance To Grab Your Favs… ✅
Sale ends TONIGHT! Last Chance to Grab Your Favs…❌

3. If you’re sticking to sentence structure — properly punctuate. For example:

Uh-oh! Your prescription may be expiring. ✅
Uh oh your prescription may be expiring ❌

TEST — Keep it Accurate.

Maybe emojis don’t quite work for your crowd. Maybe the puns aren’t landing. The only way to find out for sure what works for your audience? Testing.

Here are some ways you can be sure your subject line variations give you the answers you are looking for.

  1. Placement — The rule of thumb is usually to keep important information at the beginning of a subject line — but as we’ve said before, there’s no “one size fits all” approach. If you’re mentioning a sale, for example, including variations with the word “sale” in the beginning and the end will help you get a data-driven answer about what your audience best responds to.
  2. Variables — In any test, it’s important to make sure the variations you pit against each other will give you a definitive answer to your question. Let’s say you’re testing how your audience responds to emojis — you’ll need to include a “control” option with no emojis at all. Testing various emojis without a control may give you some interesting information, but simply won’t give you the answer you’re looking for.
  3. Timing — if you are testing two different subject line theories, make sure you are scheduling both versions to drop at the same time. This will help you get a true and fair result so that you will know how to move forward with your strategies when building subject lines.

And there you have it — you are on your way to making click-through-worthy subject lines!

You now have the tools you need to get that beautifully crafted email out the door, into inboxes and opened for your customer’s to see. By keeping your subject lines simple, clever, quick, consistent and accurate — your open rates will see an increase no matter what.

We’ll see you in our inbox ;)

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