B2B marketers work really hard to build a prospect’s interest and convert their email addresses into trust. We work even harder to craft compelling messages that entice them to stay engaged, long after that first conversion.

But your emails are only effective if they're read. And one of the most important factors that determine whether an email gets opened or ignored is the subject line. Your email copy can be exciting and compelling as can be, but without an effective subject line that compels the reader to open, your content will remain unseen.

In the world of B2B email marketing, competition is fierce. The average inbox is cluttered with streams of unopened emails, while open rates continue to hit pitiful lows. I can’t help but wonder if unimaginative subject lines hinder our success.

While there are a number of tactics and techniques you can use to help you write a clever email subject line, I thought that a little bit of research would help us draw some conclusions.

I rallied the troops here at Uberflip and asked the marketing team to conduct a quick inbox audit. We took a closer look at some of the recent email subject lines that compelled us to click, open, and read. Then we examined exactly why they were so effective.

Here's what I found.

Mind the Curiosity Gap

The curiosity gap is a powerful copywriting technique that marketers often use in headlines and subject lines to keep the reader engaged, wanting to fill a gap with new knowledge. It’s the space between what you know and what you need to know.

Subject line: Oh lord, twitter outrage

Source: CB Insights

Why it worked: There’s a Twitter outrage and we don’t know about it? The possibility that there’s some insanely crazy news being discussed on a social platform—that as marketers we’re unaware of—is enough to pique our curiosity.

Subject line: Alana, do something big in 2018

Source: Trello

Why it worked: This email was sent on January 4 (right after the holidays). The timing is impeccable. Everyone is coming back from ringing in the New Year, refreshed and wanting to do something big to meet their goals. This subject line capitalized on that thinking.

Subject line: If your boss did this, what would you do?

Source:  InVisionApp

Why it worked: They haven’t told us what our boss is doing, but they are alluding to something relevant enough to get us to react. It was a simple play on curiosity, but using the boss in this subject line was brilliant. Leveraging curiosity and including someone influential from our everyday life triggered that open.

Wordplay or Concept Play?

Subject Line: What Bananas Have to Do With Your Marketing (Seriously)

Source:  SnapApp

Why it worked: Sheer novelty. Pairing two familiar concepts – bananas and marketing – without an obvious connection piqued our curiosity. We needed to see how they were linked. Two other factors were at play here. The timing of the email (sent at 9:30 a.m., aka the banana-eating hour) worked in its favor, and we appreciated the subtle reference to SnapApp's own gorilla mascot (as we all know monkeys eat bananas). Sure, it might have been a bit clickbait-y but it worked.

Subject Line: Coco-Cola shot the sheriff

Source:  InvisionApp

Why it worked: We opened this email for some amazing wordplay that didn't steal from the headline, but made us search out the story! For content marketers, this was an intriguing use of personification that not only rolls of the tongue with good rhythm, but really has you thinking about the concept of this email.

Subject Line: You’ve done this to yourself. Super Early Bird is ending.

Source:  Pendo

Why it worked: It’s safe to assume that people love to read punchy, playful copy like this one (or Uberflip’s marketers are all just a bunch of fun people ;). The first few words of this subject line caught our attention immediately because of the serious tone, but we immediately realized they were joking. We receive so many emails that start with "Are you available?" or "Hoping you can help" that it's refreshing to see a subject line like this.

Subject line: Save $900 before you leave for the weekend

Source:  HubSpot

Why it worked: Telling us that we can save money and reminding us that it’s Friday is a pretty memorable combination! Plus, we genuinely enjoy getting Hubspot's emails from Elijah, their events manager. The tone is consistently funny and casual, making it feel more like a punny friend emailing us, instead of a thousand-plus person company.

Think Outside the Inbox

As B2B marketers, we see emails entering our inboxes with all kinds of headlines and it’s safe to say there’s always a noticeable pattern. An incredibly effective way to drive that open is by saying something that no one else has said. Everyone is telling you to create valuable content. Everyone is telling you to personalize. But if someone is offering advice that goes against it all, you’ll want to know. Say what no one else is saying.

Subject Line: Stop telling me to plan for 2018

Source:  Uplift

Why it worked: All we’ve ever been told is to plan for the new year. The new year is a time to create new resolutions, set new budgets and build new strategies (until Uplift’s email that is). This email stood out because they’re telling us to do the opposite. We wanted to know why. Maybe they have a stronger alternative to offer?

Subject Line: Why remote working will die

Source:  LinkedIn

Why it worked: Although this may seem like a classic example of claiming that a big trend is dying, this was entirely different. Usually marketers hear how email is dead or paid ads are dead, but reading that an operational trend like remote working that has been nothing but growing in a global market had a shocking effect. This email isn’t telling us that remote working is dead. It’s trying to tell us why it will die. Whether we agree or not, we wanted to know their reasons.

Us Marketers Love Shiny New Things

Subject Line: The guide marketers can’t do without

Source:  Emma

Why it worked: Whether we need it or not, we definitely want to see it.

Subject Line: 7 Must-See Email Templates You Can Replicate

Source:  Salesforce Pardot

Why it worked: We are being offered a seemingly valuable resource with more than one in the package, and we can recreate it? Sounds irresistible.

Prioritizing Personalization

Sometimes we mistake personalization with personalization tokens. Hi <firstname>, have you seen my latest post? While that sounds personable, we’re actually subscribing to personalized content, not verbiage. Does the contents of the email solve a problem we’re experiencing? Have you segmented your emails enough so that we only receive those that provide value?

Subject Line: How to Win at Trade show Follow-ups

Source: Engagio

Why it worked: This is directly relevant to Uberflip and sounds like they have a winning formula. For companies like ours that invest our time heavily in conferences and big events, this email was segmented beautifully and sent to our marketing peers who handle events and follow-ups. They are serving up personalized content that aims to solve one of our email marketing challenges.

Your customers and prospects are demanding personalized experiences more than ever today. As marketers, it's our responsibility to prioritize personalization and deliver creative openers that will resonate with our buyers.  Don’t let irrelevant subject lines hinder your prospects’ content experience.

Key Findings

Reactions to email subject lines can be subjective. I may open an email with a fries emoji in the subject line, but that doesn’t mean everyone will. It’s more crucial than ever to segment your lists and keep your subject lines highly targeted. 

Most importantly—don’t forget who you are. Not all techniques will necessarily work for your brand and voice, but that doesn’t mean you have to be boring. And finally, have fun with it! People appreciate some thought put into getting their attention. What’s a few extra minutes brainstorming more enticing subject lines? 

Happy emailing! Hope to see yours pop in my inbox.

Want to make your emails sing? Check out 9 Proven Ways to Boost Your B2B Email Performance.