Email Subject Lines: 8 Secret Steps To Increase Click Rate

Jasmin Hukic, 2017-01-11 20:01:41

You’ve probably heard so many times that email marketing is still the best email marketing channel because of its ROI and many other reasons as well. Indeed, you shouldn’t have doubts about investing in it, but if you’re still not convinced I suggest to read more about email marketing. An average business user sends and receive a lot of emails and according to Radicati, that number is 123 emails a day. Emails per user stats Having that in mind, to get good open rates you will need the perfect subject lines. In writing effective emails subject lines are the first step and they should be attractive, eye-catching, curious and much more. Therefore, in this blog post, I’ll show you how to write subject lines to increase your open & click rates.

#1 Segment Subscribers

What segmenting customers has anything to do with subject lines? A lot more than you think. Segments are groups with certain similarities and based on that some subject lines will trigger better than others. Customer Segments

Source: optimoveblog

For example, let’s say you segment people by age and then target ones who were born in 1987 - they will be 30 years old in 2017. In subject line, you can offer presents for this special year for them. This way segments allow you to create more personal subject lines which will result in better open rates. The more data you collect the more segmenting options you’ll have.

#2 Understand Psychological Principles

Human psychology is definitely your playing card in writing emails. This especially counts for B2C businesses but it’s also very applicable in B2B’s. You’ll notice that in every quality text about CTA’s (Call-to-Action) the psychological moment is mentioned, including the psychology of colors, numbers or phrases. Why am I bringing this up? Because subject lines are nothing but a call to action of its kind. Here are some general rules about people's behavior that you can use in writing subject lines:
  • Fear of missing out is irresistible
  • Curiosity is humans natural desire
  • Humor is the best trigger
  • Vanity is part of us
  • Greed is part of us (we’re unwilling to admit but it’s true)

#3 Include Numbers

When you put numbers in email subject lines you are going more specific and that’s always a good thing because people don’t have time to explore what’s inside. Numbers in subject lines The test from Marketing Experiments clearly shows how numbers in email subject lines can increase open rate & click rate. Among dozens of emails in recipients inbox, subject lines with numbers will be more eye catching and you’ll have better chances to be seen.

#4 Use Magnet Words

Knowing that email recipients have so many messages to read, you should ask yourself what motivates them to click. Earlier we’ve concluded that numbers will increase click rates, but the question is what words should you be using? Again, it’s A/B testing that will discover trigger words for you. But you should have some idea to start with. There are tons of suggestions all over the internet. My recommendation are 48 ubiquitous power words from Linda Ruth and Curtis Circulation Company: Improve, Trust, Immediately, Discover, Profit, Learn, Know, Understand, Powerful, Best, Win, Hot, Special, More, Bonus, Exclusive, Extra, You, Free, Health, Guarantee, New, Proven, Safety, Money, Now, Today, Results, Protect, Help, Easy, Amazing, Latest, Extraordinary, How to, Worst, Ultimate, Hot, First, Big, Anniversary, Premiere, Basic, Complete, Save, Plus, Create.

#5 Consider Subject Line Length

Just like anything in email marketing, subject lines can and should be tested all the time. You can perform various tests like length, words, numbers etc. One of most common doubts is whether to use long or short subject lines. It seems reasonable to expect that short subject lines will perform better, since people quickly scan subject lines in their inbox, and too long lines will fail to grab attention. Still, researchers like Return Path's claim otherwise: Subject line length and average read rate The Art and Science of Effective Subject Lines report:
Our research indicates that there is actually no correlation between the length of a subject line and its read rate. When comparing the number of characters in a subject line to the read rate, the Pearson's correlation value was - .03, which shows us that there's no relationship between the number of characters in a subject line and whether or not the email is opened.
So what should you do? Test, test, test. Don’t hesitate to use long subject lines, and eventually, you’ll find your optimal length.

#6 Use CoSchedule’s Headline Analyzer

Before final decision about the subject line, I strongly suggest checking it with CoSchedule’s Headline Analyzer. Let’s imagine that you’re sending 15% of discount to your subscribers, with the following subject line: CoSchedule Analyzer Click on Analyze Now and you’ll get the results based on Common, Uncommon, Emotional and Power words: CoSchedule Grade I got the B+ with a recommendation to improve the balance. I could do that with importing an uncommon word since I have none in the subject line. However, this analyzer is primarily a headline checker so I’ll scroll down the results to see if I can find something useful related to my subject line. I can see how the subject line will look in an inbox: Subject line in inbox In this case, it’s very important to have 15% Discount visible, because more than 60% of emails are opened on mobile devices and there is a risk that in longer subject lines important parts may not be seen. After some more scrolling I can see another important note: Sentiment in subject lines Positive sentiment is exactly what to achieve, so I’m pretty satisfied with my subject line.

#7 Email Subject Line Keyword Checker

OK, we’ve tested our subject line, but what about the keywords? For that purpose, we can use subject line checker Adestra. Let’s use the subject line from previous example and see if there are better alternatives to keyword discount. Choose a Sector Retail/Ecommerce, paste the keyword discount and click on Check my keyword: Subject line checker discount Both open and click rate are significantly below the average, so I could consider some synonyms like a price cut: These results show that keyword price has much better rates. Unfortunately, this checker shows the result only for one word, not the phrase. In other words, it’s possible that term lower price would be even better than price cut (here is the idea for A/B test).

#8 Track Your Results

In every part of email marketing, you simply need to measure everything. Using tools like jellymetrics you can track your click rates of your campaign. But how will you know if your performance is good enough? For that matter let’s see some useful benchmarks. According to emfluence, an overall average open rate is 22.17% and click rate is 3.74%.   A lot depends on the industry. For example, the banking industry has the highest open rate - 30.06% because people are interested in newsletters from their banks. Another intriguing fact is that 50% of Americans check their email while in bed. In other words, if you don’t have an interesting subject line, they will pass your email.


No matter how good content your email message contain, a bad subject line can easily crush your campaign. That’s why writing good subject lines is the activity that deserves a lot of attention. If you take all the steps from this text, there is a great chance that you’ll improve the click rates. In these steps I didn’t mention arguably the most important activity - A/B testing. I didn’t do it because A/B testing covers up everything - numbers, words and subject line length. Do you have any experience with subject lines? Share in comments.