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Article first published in January 2015, updated June 2019

Do you find it difficult to write great email subject lines?

Although there are a number of subject line formulas that can help, it can be hard to know if what you’re writing is really resonating with your audience and compelling them to open your emails.

That’s why, when we learned that headlines with a high Emotional Marketing Value (EMV) increased conversions, we wanted to dissect the process and share it with you.

So, in this post, we’ll show you how to use the EMV Index to improve your email subject lines and increase your open rates.

What is the EMV Index?

Back in the ’60s and ’70s, government research scholar Dr. Hakim Chishti was studying the roots of several languages including Persian, Aramaic, Hebrew, Arabic, and Urdu.

In his research, he found that there are basic underlying harmonics in language that are always interpreted with the same “emotional” reactions. While the meaning of a set of words can be mistaken, the sound tones made when those words are said in a sentence are always interpreted the same way in our emotional response.

From these findings, the EMV Index was born. It’s essentially an algorithm that assesses how a group of words follows these emotional harmonics, and how likely they are to elicit an emotional response from a reader.

So, in the context of email marketing, it can be used to assess how much of an emotional response a particular set of words (like a subject line) will generate.

A perfect EMV Index score would be 100% but that’s rare, unless your subject line is quite short. A good score would rank anywhere from 40% to 75%.

How does EMV vary from other subject line methods?

With so many creation and testing tools for subject lines, what makes the EMV method different from other subject line creation methods?

1. Pushes emotional buttons

Research has proven that people don’t buy into a product for logical reasons. Often times, a buying decision is influenced by emotions. If, as a marketer, you’re able to push the right emotional buttons (or triggers) in your target audience, it becomes easier for you to sell.

What does this have to do with your subject lines?


Subject lines that tug at the heart are more likely to lead to higher conversion rates than those that don’t stir a reader’s emotions. Below is an example of an emotionally charged subject line that elicits a click:

Source: Gmail

Everyone craves to be inspired to excel at what they do. That’s exactly the need the headline above is promising to meet. A reader’s response would be to immediately open the email to find out the secret to supercharged writing.

2. Creates a lasting impression

Subject lines crafted using the EMV method don’t just tug at the heart, they’re also so powerful that they make a lasting impression on the reader. Of course, one of the main purposes of marketing is to ensure that your brand is always top of mind when your customers need a product or service you provide. A powerful, emotionally charged subject line will help you achieve just that.

3. Triggers viral responses

We live in a world where ad blockers have become the norm and people decide which type of content they want to consume. The best way you, as a marketer, can increase the chances of your message being seen is by creating content that people will want to share.

For the email marketer, the gateway to viral emails is the subject line.

By creating a subject line that people love, you increase the chances of your email being forwarded or triggering a word of mouth campaign. Most of all, you can make it easier for your readers to share your email on social media by including share buttons in the email.

According to research, people put more trust in content that’s shared by other people (earned media) than content shared by a brand (paid media).

What’s the difference between paid and earned media?

So what’s the difference between paid and earned media?

Paid media

Paid media refers to any channel that you have to pay for in order to get your message to be seen by your target audience. Common examples include display and banner ads, PPC campaigns, and promoted content on social media, just to name a few.

Source: Facebook

Earned media

Earned media is, in essence, exposure gained through the sharing of content, brand mentions, shares, reposts, and other forms of online word of mouth. Earned media value, therefore, is a measure of the worth you receive from content that’s shared on various platforms.

How to use the EMV Index to write better email subject lines

Now that you understand what the EMV Index is, it’s time to put it to work writing better email subject lines.

By following these steps, you can compose email subject lines with high EMV scores that lead to more opens (and more conversions.)

Step 1: Write 25 potential subject lines for your email campaign.

Viral website Upworthy has a policy where writers have to write 25 potential headlines for every post they publish.

Whilst it may seem like a lot of effort, it forces you to think outside the box. When Garrett Moon of CoSchedule started to apply this to his own headline-writing efforts, he found that the headlines he wrote got better as he went on. The first 10 or so were easy to come up with but were pretty basic and obvious. After that, he had to start getting creative in order to come up with the next 15, and, as a result, he found that the final headlines he wrote were often the winners.

Spend some time writing a number of different subject lines for your email campaign, as it’s likely your best one will take some time to come up with. If you need help, check out this list of power words in email subject lines.

Step 2: Run them through the Emotional Marketing Value Headline Analyzer.

The Emotional Marketing Value Headline Analyzer is a tool from the Advanced Marketing Institute that analyzes headlines and tells you their EMV score.

Used in an email marketing context, you can simply enter your subject lines into the tool and it’ll return a score between 0 and 100 based on the emotional marketing value of the subject line you created.

To use this to write better subject lines, take the 25 different subject lines you wrote in Step 1 and run them through the tool, making sure you keep track of the score of each subject line.

Let’s say, for example, that you’re planning on confirming an event invitation. Here are two versions of subject lines you could use. The first is before tweaking using the EMV method:

Source: Advanced Marketing Institute

While it may seem to be a good subject line, it definitely can be improved on:

Source: Advanced Marketing Institute

Step 3: Use the two highest scoring subject lines in an A/B test.

When you’re setting up your email campaign in your chosen email marketing software, utilize a subject line A/B test and enter the highest-scoring subject lines from your original list of 25.

If you’re a Campaign Monitor customer, the tool will then send a version of your campaign with each subject line to a small portion of your list, then, based on which email gets the most opens or clicks, it’ll automatically send the winning subject line to the rest of your list.

Source: Campaign Monitor

Finally, you’ll get a report that shows you which one is the winner, and how many extra opens and clicks you got by running the A/B test.

Wrap up

Better subject lines mean more opens of your email campaigns, and more opens leads to more click-throughs, more conversions, and more revenue for your business.

So, for your next newsletter or announcement email, try writing a number of different subject lines for your email campaign and use the EMV Index to decide which ones to A/B test. You’ll end up writing more emotional subject lines that appeal to your target audience and get your emails opened.

Speaking of getting your emails opened, check out our article on how to improve your email open rates.

This blog provides general information and discussion about email marketing and related subjects. The content provided in this blog ("Content”), should not be construed as and is not intended to constitute financial, legal or tax advice. You should seek the advice of professionals prior to acting upon any information contained in the Content. All Content is provided strictly “as is” and we make no warranty or representation of any kind regarding the Content.
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