Subject lines are the ultimate underdog in the marketing world. They are your first, and potentially last, impression on prospective customers—be sure to make them count!

Not sure where to start? You’re not alone. As we study the importance of eye-catching subject lines for email marketing campaigns, we’re able to glean further information on what works best to increase open rates for any email campaign. 

Lucky for you, we’re sharing our findings!

Check out this special list of 5 ways to improve your subject lines so you and your team can be sitting pretty in 2021. 

Note: We acknowledge some of these tips contradict one another. These points are ultimately suggestions to try out for upcoming email campaigns. Experiment and record your findings! What works for you won’t work for others and vice versa.

Be a rebel. Try new things. 2021 is your year.

1. Try simple, no-nonsense email subject lines

We know—this doesn’t sound fun to us, either. Who doesn’t love a witty email subject line packed with pop culture references?

However, in the spirit of transparency, try being more upfront about the contents of the email. You have nothing to hide, right? Let your customers and leads know what they can expect when they open the email by trying an honest and upfront email subject line. 

Groundbreaking? Not really, but in an age where we’re bombarded with marketing gimmicks and click-bait headlines, it can be refreshing to encounter a simple email subject line that’s honest about its intent. 

Sure, this isn’t the most fun way to kick off a year, but you might be surprised by the results of taking it back to basics! Save your brainpower for the contents of the email. It’s worth a shot!

2. Keep ’em short!

Short: we’re talking six to ten words.

In our October blog post, “How to Increase Email Open & Click-Through Rate,” we shared a few ways to spice up your subject lines and made sure to highlight subject line length. This has continued to be a hot topic in the digital marketing world and almost everyone recommends something different (sometimes shorter, but rarely longer). 

Why do we recommend six to ten words? Retention Science shares that subject lines with six to ten words deliver the highest open rate overall, and since Net-Results serves customers from all different backgrounds, this is our preferred sweet spot. 

That being said, we do enjoy taking a risk everyone now and then. This leads us to…

3. Single-word subject lines

According to the same Retention Science report, subject lines with zero to five words had the second-highest open rate. Sidenote: We’re not sure who is sending email campaigns without a subject line, but maybe they’re onto something? (not likely *insert emoji in the final post*)

Take a minute to look through your inbox. How many one-word subject lines do you see? Most likely, none. That’s the whole point!

Email subject lines composed of a single word are guaranteed to stand out amongst the hoard of emails in your customer’s inbox. We call that a win. 

From a design perspective, this single-word subject line catches the eye of your leads and allows it to stand out from the “subject line” crowd. 

Your subject line is the ultimate star of your email. Let her stand alone and she is guaranteed to shine.

4. Personalization

Who doesn’t love hearing (and seeing) their own name? The same psychology applies to subject lines. Customers love personalization, so why not start with the first thing they’ll see?

Along with first names — we don’t recommend using last names unless you have a really good reason to do so — you can also personalize fields such as city, state, country, and so much more with Net-Results Marketing Automation Software. (Several competitors may say they offer similar features, but our personalizations are second-to-none in the marketing automation industry.)

But don’t take our word for it! Schedule for a quick chat now to find out how your team can drive conversions and sales by incorporating Net-Results personalizations into your next email marketing campaign. 

Personalizations allow your email to stand out, much like single-word subject lines. When people see their own name or location, they’re more likely to take a second look. In fact, Retention Science’s report discovered that email subject lines personalized with a recipient’s first name lifted open rates by 2.6 percent. Not too shabby!

5. Scarcity tactics

We’ll be upfront: USE THIS TOOL WISELY.

No one likes drama, and if you’re constantly bombarding your subject lines with messages of scarcity, you might be sending your subscribers straight to the “unsubscribe” bottom. Yikes!

That being said, email subject lines that incorporate scarcity (i.e. ‘only xxx items remain!’ or, ‘48 hours only!’), tend to perform well. FOMO is real, so why not use it to your advantage?

However, you do not want to be the company that cried wolf. If your subscribers routinely see scarcity subject lines like these, they may start to ignore you or doubt your claims. Sprinkle them in here and there (when they’re actually true) and use your best judgment. Your open rates will soar with the thoughtful use of scarcity tactics!

By the way, if you’re having trouble getting to the inbox in the first place, check out our free Deliverability Guide. It includes all the information you’ve ever wanted about Email Deliverability like how to increase the number of your emails that reach your target’s inboxes, the best practices our best-in-class Customer Success team pass along to our customers, and common mistakes we see when it comes to emails. 


For some teams, subject lines are a last-minute decision. In honor of the new year, consider making subject lines a priority for your upcoming email marketing campaigns. Careful, considerate strategy behind subject lines is a gamechanger for most teams, so get this year started on the right foot!

By incorporating these tips and upping your email marketing game, you’re sure to see better open rates, leads, increased revenue, and more. The world is yours—live it up, marketers!

Ta-ta and Happy New Year!,

Lexie Robbins

Digital Marketing Specialist

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Alexis Robbins