A Psychological Based Analysis of Marketing Email Subject Lines 

A Psychological Based Analysis of Marketing Email Subject Lines 

Since its inception in the early 1960s, email has gone on to radically transform our lives. As the technology has become more accessible, marketers have embraced the ability to directly communicate with their consumers, sending messages directly to the smartphone in their pockets. With this capacity, it’s easy to see why email marketing has become invaluable to businesses around the world.  

Email marketing could be classified as any email a business sends to a current or potential customer in which they send advertising material, request business, or solicit sales and donations. More recent marketing strategies have sent communications with the aim of building brand awareness, trust or loyalty. Email marketing has become so popular with businesses for a number of reasons. It is much cheaper than sending traditional mail and can appear almost instantly in front of their consumer. There are also more opportunities to gather analytics from emails. Marketers can analyse who opened their emails, when they opened them, which links they did or didn’t click and use this information to optimize their future messaging. Partnered with an effective marketing and sales funnel, email has become a powerful tool for businesses. 

To achieve any success with Email Marketing, you first need to persuade the reader to open the email. The main deciding factor in a reader’s choice, to open or delete, will be the subject line.  

At present, there has been little scientific research into what triggers a person into opening and reading an email. A recent study however used natural language processing, text analysis and computational linguistics to identify what these triggers were. The research analysed the email subject lines from a psychological point of view and determined what effect it would have on a person reading it and what decisions they would make to open that email or neglect it. The objective of the research was to develop methods that could quantify the psychological effects induced by an email subject line; and correlated this with the action performed by the email receiver.

To conduct the study the researchers used sentiment analysis and data mining on three large data sets from Enron Email, Spamdex Digital Spam Archive and Google Open Adwords. The study concluded that for a subject line to be successful it would need to follow a series of rules. These rules stated there were a series of elements that would contribute to the success or failure of an email. 

Emotion

One of the key factors was determined to be the emotion conveyed within the subject line. Unsurprisingly it was found that a subject line with a positive emotion word received more opens, while a negative emotion word received fewer opens. The study also looked at blending emotions within the subject line. It found that a mixture of joy, surprise, anticipation and trust could create an increase in opens, were as a blend of sad, fearful or angry emotions would result in fewer opens. Perhaps surprisingly it was found that blending negative emotions with surprise or anticipation could generate an increase in responses/replies to the original email. 

Polarity

Another factor found to contributed to the success of an email subject line was the use of polarity. The use of positive polarities such as “is” or “have:” were found to have a much better open rather when compared with negative polarities like “is not” or “have not”  

Phrasing

There are many opinions on the length and theme of phrasing to use in a subject line. This piece of research found that if a subject line is more subjective or personal to a reader it is more likely to hold their attention for longer. Including the name of your business, organisation or brand were also found to include open rates. Interestingly the research also found that starting an email with an adjective such as “many” “few” or “fast” would limit the number of clicks an email received. 

In terms of length, the study found that if the subject line had less than three phrases It would not generate a high level of clicks. The study also looked at some of the terms and related words that would affect the success of an email. It found that those containing business-related terms performed better than those that included terms relating to entertainment or travelling. 

Sometimes however the terms used for the same subject could achieve very different results. If we look at the term “Shopping” then including words like “% off” “sale” or including prices and discounts would result in a higher open rate. In contrast terms like “free” or “coupon” were found to limit the open rate. Looking at business terms, words like “turnover” or “millions” would have a much better impact on readers than words like “webinar”, “seminar” or “conference. ”

Words & Characters 

When looking into the number of words a subject line should use the study concluded that a subject line with between 7 and 8 words would get the most opens. Luckily for times when it’s not possible to have that many, the study also found that using more than 4 words would also draw a favourable number of clicks. It also found that the use of longer words, capitalising the first letter and separating the subject line with pipes (*-*-*-) would also generate a higher number of clicks. 

The study also drilled down into the number of characters to use within an email subject line. It found that having more than 80 characters was favourable. In comparison using between 50 to 80 characters would generate less click and using less than 15 would generate even fewer. 

From the research, we can see that there are many factors to consider when crafting your email subject line. It is important to remember it’s not possible to follow each finding that this study concluded would bring a higher rate of clicks. For example, it would be difficult to construct a subject line of 80 characters and 7 words! Their findings however can serve as a guideline for marketers when next selecting what to put in that all-important subject heading.