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Email subject lines: 5 B.S. “facts” that everyone thinks are true

If 2017 has taught the world one thing, it’s that “facts” aren’t always facts.


Between researching, designing, testing and creating Phrasee’s artificial intelligence subject line generation technology, and tracking the progress of the millions of email subject lines it has generated, we’ve learned a thing or two about what works and doesn’t. We understand the ins and outs of what makes a subject line successful. We also know what doesn’t have much impact at all.

We’ve read many posts and articles about email subject lines over the years. Many have been well researched and have used quality statistics to make their case. From these we have learned some useful facts about email subject lines. From others, using bad statistics and less than stellar research, we have been offered nothing but “facts”, things which sound convincing at first glance but simply do not hold up against any kind of reasoned statistical analysis.

Here are 5 of our favourites…

Email subject lines: 5 B.S. “facts” that everyone thinks are true


“Fact” 1: Every word matters!


We’ve said it before and we’ll say it again – sentiment is more important than any single word in a subject line. Yes, the words we choose to represent our brand, get our message across and connect with our target audience matter, but they matter more in relation to one another and in the underlying sentiment that they convey.

Think about it, when you speak with someone, don’t you remember much more about how they made you feel than the individual words they used? The same holds true for email subject lines. Anyone who tells you that changing a single word in a subject line will significantly impact how that subject line performs probably doesn’t know what they’re talking about.  

Analysing the underlying sentiments a subject line conveys is actually much more useful than analysing the individual words used.

How do you do that? Funny you should ask because it just so happens that we can help you out with our Phrasee Pheelings™ sentiment analysis engine. Built by marketers for marketers, this powerful tool quantifies the direct marketing sentiment in your email marketing language. Give it a whirl here.

“Fact” 2: Using 😄 emojis 😄 has a big impact on open rates  📬

Love ‘em or hate ‘em, it looks like emojis are here to stay.

A survey by Experian (which has since been taken down) claimed that 56% of brands that use symbols in their subject lines see a higher open rate. The results also claimed that marketing emails with emojis in their subject lines were opened 45% more often than emails that didn’t use emojis in the subject lines.  

But do they really work in getting people to open an email? Yes… and no.

What emojis certainly do is amplify the language contained in your subject line. Obviously, they can help your subject line stand out in an overflowing inbox (at least until everyone else is using them, too). They can amplify a good subject line and make it pop. If your message is on point and directed to the right target, this amplification can mean that your email totally hits its mark. However, if your content is poorly created, off message, or not targeting the right consumer, the emoji then amplifies the mess.

Basically, the humble emoji has the power to make a good subject line better, and a bad subject line worse. Proceed with caution!

“Fact” 3: It’s what’s inside that counts


True, the content of your email is going to be what makes or breaks your conversion rate, however, you need to get people to open your email first, and the subject line is what makes that happen.

If you put all your energy and resources into creating the perfect marketing email, and then hastily throw together an email subject line because your ideas are all used up and “it’s what inside that counts”, you’re doing yourself and your company a major disservice.

Would you spend millions on creating a new widget but then try to sell it in a brown paper bag?

We sure hope not.

Commit to spending some time and effort on crafting a smart subject line considering the email’s content, your readers and what you think they’d be most interested in clicking on. Then, test, test, and test some more

Be bold! (but maybe not this bold.)  

“Fact” 4: Length matters

While length may matter for some things, email subject lines are not one of them.

There are many numbers out there about the supposed optimal length of email subject lines, but the truth is there’s no sweet spot for length when it comes to crafting clever subject lines that make recipients go, “Yes – YES! I must click and read this whole email now!”.

In fact, subject line length accounts for just 0.1% of email open rate variance.

How do we know this? Maths, baby.

We love to geek out on numbers (and crusade against bad statistics) and have run a number of tests and formulas analysing hundreds of thousands of marketing emails to check the correlation between successful subject lines and word count. We have also consistently found that there’s no correlation between the two. (Want to know why? Read all about our methods and findings here.)

“Fact” 5: Subject lines don’t need to be on-brand, they just need to produce opens


Umm… not true. This misconception is related to the false idea that it’s just what’s in the email that matters most. Maintaining your brand’s voice should be considered first and foremost across all your company’s communications all the time. Period.

We get it, drafting email subject lines is hard. Conflicting or B.S. information on what you ‘should’ be doing coupled with the pressure of consistently producing solid copy and subject lines that convert can burn out any email marketing brain. Fortunately, we’re here to help lighten the load – learn how Phrasee can help make your next email marketing campaign more effective by booking a demo now!

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