Email marketing is all about getting the attention of your audience. The first part of your message anyone will see is the subject line, and getting that right is paramount. Many articles give advice on the words you need to use in your subject line, but they often fail to mention the length.
Having all the power words within your content may do you no good if you have a subject line that is too long to read. So what is best: short or long subject lines?
Not All Data Suggests The Same
The biggest problem with determining the ideal subject line length, is that not all the data is the same. It is all dependent on what campaigns are measured and the audience who received those campaigns.
For instance, those sending messages to the B2B sector will find that messages with subject lines of between six and ten words will get more open rates, but click through rates aren’t great. When there are more than 130 characters, the open rates drop significantly but the click through rates increase substantially. Finally, anything over 16 words sees a significant return on both clicks and opens.
The president of ShowMeLeads has claimed that she has found a definitive answer for the length of an email. Research that analysed 260 million emails from 540 campaigns has led her to believe that there is a very specific word count that businesses should aim for.
According to the research:
- Subject lines with between six and ten words generated a 21% open rate.
- Subject lines with fewer than five words were opened on average 16% of the time.
- More than half of emails had between 11 and 15 words in the subject line and generated a 14% open rate.
Marketing Sherpa conducted research to find out whether or not longer subject lines were better than shorter messages. They looked at 9,313,885 emails for their research. Their results were different than those of ShowMeLeads.
Their results were as follows:
- The most popular length for subject lines was between 41 and 50 characters, yet it performed the first worst for open rates.
- Only 6% of emails had a subject line of between 61 and 70 characters, but these had the best open rates (17%).
- Email messages with between 51 and 60, or 91 and 100 characters performed the second best achieving 15% open rates.
Finally, Return Path studied over 2 million emails to evaluate the correlation between subject line length and open rate. Their research also looked at the Pearson’s Correlation value, which suggested that there was no correlation between the length of the subject line and open rate.
However, they still advise keeping an eye on your subject line length. Their research demonstrated that:
- 25% of subject lines were between 41 and 50 characters.
- Open rates were greater when subject lines were between 61 and 70 characters.
- Only when there were more than 100 characters in a subject line did the open rate drop (down to 9%).
Desktop Versus Mobile
One of the important considerations is the device that your email is being read on. Desktop inboxes display approximately 60 characters whereas mobile devices show between 25 or 30 characters. Therefore, if your audience is mainly on mobile devices, then you need to shorten your subject lines, so the call to action or important message is at the beginning.
Email subject length might be an important factor in the success of your campaigns, but there is little evidence to suggest that a longer or shorter one will have a major impact. It might be all too dependent on your primary audience. Therefore, you should consider A/B testing your emails when deciding what works best for your audience.
What subject line length do you use? Have you ever tested it?
Let us know in the comments below.
We are often told that size doesn’t matter. Well that is wrong. Size does matter when it comes to your email subject line. It is the first impression your audience will have on what is contained within your marketing message. It needs to entice them to open the email and red further. Therefore, the subject line needs to be alluring, indicate what the message is about and not give away the whole story.
This can be a difficult balancing act. Most people think they need to write an essay to achieve all three. While this can help, it can also be tough to read. Some try for the shortest email subject line they can manage. Yet this can seem non-descriptive.
Both camps claim they have the answer; yet, only research will tell what the impact is on the open rate for campaigns.
The Adestra Research Project
Adestra compiled some results from email marketing campaigns they were monitoring. They looked at how people interacted with a message and compared that to the email subject line. The results they saw were rather interesting. Firstly, they spotted that there was a sizeable bump in success when subject lines were between 10 and 30 characters long. Results either side of this mark were less than half.
Subject lines of this length are often offering a deal (i.e. Claim your 50% off today, etc). Therefore, it is normally business to customer messages that achieve success while being short.
Yet this wasn’t the only interesting result. Subject lines that were between 30 and 70 characters long achieved less than average responses while those over 100 characters seemed to perform well.
There was a particularly good set of results when email subject lines were 130 characters long.
Another study conducted by the president of ShowMeLeads, Madhu Gulati, found another set of results that could turn the results above upside down. According to their research into 260 million emails sent during 540 campaigns, they found the following results:
- More than half (52%) of campaigns contained 11 to 15 words in the subject line. However, it had the poorest open rate.
- Those campaigns that contained between six and 10 words received a 21% open rate.
- Short subject lines (five words or less) had 16% open rates.
These results are almost in contrast to what was previously reported on Adestra.
MailChimp has also studied the problem. They came to the conclusion that length meant nothing and that it was the reader’s tastes that determined whether they would open your message up or not.
While there is some truth in this, looking at the MailChimp results there is something of note. Their results show an above rise in opens and clicks when the subject line is short. According to their data, you are bound to get the best results when your subject line is between 15 and 22 characters long.
This is rather important as it correlates with the other two studies.
It is important that click through rates shouldn’t be a huge factor on whether your subject line is best. Once the audience is at this point, other factors are determining their behaviour.
It is also important to note that none of these studies decided to a/b test the subject lines of exactly the same email to test the results. This might have given a better answer to the question.
To optimise your emails for your audience, consider a/b testing your email campaigns.
There are varying thoughts on what is the right length for an email subject line. Many consider that long subject lines distract audiences and lower success rates, yet others have demonstrated this is not the case. What all the studies do show is that a short, concise email subject line is going to perform better than the average.
What is the average length of your email subject line? What have your results been from your previous subject lines?
Let us know in the comments below:
- Use a short subject line to generate more opens.
- A/b test your subject lines to see what gets the best results.
You’ll hear lots of talk about subject lines when researching email marketing.
There are subject line best practices like:
- Keep subject lines short
- Use brand names in the subject line
- Use words like “New” and “Favorite” in your subject lines
These are all great tips, but there is really one simple rule to follow when it comes to creating subject lines. And you’re probably going to be disappointed when you read it because it’s something that’s not really a breakthrough idea at all.
That’s it. That’s all there is to email subject lines. I think we tend to over think our email subject lines. We think about what will get people to open them, which is good, but we don’t give enough thought to what really makes people click. We ignore the psychology of email subject lines.