Have Email Subject Line Best Practices Been Lying to You?

By: Andra Kubulins | July 30, 2018 | Smart Messaging

You’ve just received the final edits from your design team, the email campaign is set to launch tomorrow morning, and you sit down to write a subject line. Every idea you type seems too bland or too gimmicky. A quick Google search on “subject line best practices” returns 170 million results. Surely you’ll find something to spark that creativity, to write the ideal subject line to generate tons of opens.

Upon delving into just a few of these articles, you may begin to notice something a little funny. The first article you read insists the ideal subject line, crafted to drive opens, is between 60-70 characters. The next article suggests subject line length doesn’t matter at all, and yet another states unequivocally that you will get the most opens with a subject line between 30-40 characters in length.

It doesn’t end with subject line length. There are many contradictory tips and ambiguous guidelines outlined as “The 10 Official Requirements of the Perfect Subject Line.” “You must personalize” is most often included in these lists but there are sources that show mixed evidence, warnings how easily this tactic can backfire, and some articles that suggest personalization is key, as long as you use anything but the recipient’s first name.

“Be concrete in your subject line language” stands in stark contrast to the suggestion of piquing curiosity by writing a vague descriptor, and saving the details for your email body copy.

“Say free!” “Don’t say free!”

Use humor – but make sure you’re not too funny.

Should I incite a sense of urgency? Sources say: mixed results, ask again later.

Reading through so many conflicting articles all on the same topic, many of which are supported by their own evidence highlighting actual results, is enough to make you want to pull your hair out.
It’s no wonder most of us save writing the subject line for last. For such a short string of words (wait, was that 30 or 70 characters?) it causes a lot of confusion. But the care placed in improving your subject-line game is not misplaced. After all, an email subject line is the first impression for the value of the content that lies within.

Allow me to digress from the subject line topic for just a moment. I’d like to briefly chat about two professional basketball players, Rick Barry and Wilt Chamberlain. An idea, I must admit, I got from a Malcolm Gladwell podcast, and not because I am an avid fan of basketball. Both of these players were greats; indeed, they are both members of the Basketball Hall of Fame. But what I’d like to discuss is their free throw techniques.

If you’ve ever watched a game of basketball, you can probably imagine a player at the line, shooting a free throw overhand. That’s the approach nearly all players take, and on average there is a ~75% overall free throw average in the NBA. This has been true since the 1950s. So when a player like Rick Barry averages 90% in successful free throws, and a player like Wilt Chamberlain barely surpasses 50%, they both stand out for different reasons. They are polar opposites on the scale – Rick Barry is one of the all-time-best free throw shooters, and Wilt Chamberlain is one of the all-time-worst free throw shooters.

Barry diverged from the rest of the pack in his style. When he approached the free throw line, he did not execute the shot in the way that you pictured a few seconds ago. Instead, Rick Barry took his free throw shots underhand, ignoring the ridicule about his so-called “granny-style.” Chamberlain, on the other hand, try as he might, struggled to improve his percentage. During the 1961-62 season, however, he managed to improve his FT percentage to his career-high of over 60%. In this season he began shooting his free throws underhand.

In fact, this is the same season when Chamberlain famously earned 100 points in a single game. A game during which he sank an unprecedented 28 out of 32 free throw attempts, for an 87.5% free throw average. Surprising for one of the worst free-throw shooters ever. However, he didn’t stick to the underhand technique, and his FT average quickly returned to the 50% range.

Why do I tell this story? Both Rick Barry and Wilt Chamberlain had hundreds of other players to look to for “best practices” when it came to free throw style. Barry tried something different, and it worked for him. He stuck to it and greatly outperformed his peers throughout the duration of his career. Chamberlain went along with popular wisdom, and it didn’t work out so well for him. He did improve for some time by testing a new style, but he didn’t stick with the new technique that allowed him to achieve his best results.

This is where I expect some of you ferocious basketball fans will point out that Steve Nash is the all-time leader in free throw percentage, and he shot overhand. True. Nash’s average is not that much higher than Barry’s, but he still tops the list. I would like to point out, though, that Steve Nash created his own ritual that varies from the pack, and may play into his free-throw success. When Nash approached the line, he would take an imaginary shot without the ball before making his actual attempt. When you look at overall numbers between first-shot percentage and second-shot percentage, Nash leads the way. Could it be that his ritual of activating his muscle memory before his first-shot improved his stats?

But this is not the place for a basketball debate. I’ll leave that to people with deeper knowledge than what they can find through podcasts and Google. Remember when I mentioned the overall free throw average in the NBA has been around 75% since the 1950s? That kind of stagnation in results is the danger of sticking with “best practices” and not going out on a limb to try to find the technique that will work for you. This is where I really wanted to include some strong statistics to show that email open rates also have not risen drastically over the past, say 10, years. But surprise – I found a lot of mixed evidence on that topic as well.

Some research I found showed clearly that open rates have remained flat, others suggest a decline, and a few believe they have risen slightly over the years. It’s pretty unclear, although I’d like to assert that the mixed research I found would indicate there has not been a dramatic and undeniable improvement in open rates over the past decade. As an aside, you really can find anything on the internet.

Although one company found that email open rates improve in the second half of the month, I wouldn’t suggest you hold off on pressing the send button until the 15th. But there may be some astrology-enthusiasts reading this blog post who would be interested to note that moon phases may be impacting your spam complaints.

At the end of the day, your best practices have to be just that – yours. Too many thought-leaders make broad generalizations across varied industries and brands and make sweeping claims to have found the best ingredients for the perfect subject-line recipe. Just because someone has defined their own best practices doesn’t mean it will translate perfectly to you. Know your voice, know your audience, know your brand.

One place I do agree with the majority of those 170 million Google search results (I assume, based on extrapolation…disclaimer, I did not read all 170 million articles) is in testing. Take those best practices with a grain of salt, but certainly test to see if they work for your brand. And please, try something new!

Ultimately it only matters what makes your email subject lines perform best for you, whether it’s documented in someone else’s article or not.


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Author: Andra Kubulins

Andra Kubulins is the Lead Solution Consultant at Kahuna. She has worked with countless companies to advise in new MarTech solution selection to drive value for brands. She is a published author in two academic journals, Communication Reports and Communication Research, and has contributed to the Oracle Customer Experience blog and Profit Magazine.

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