Subject lines are often given the least time and effort when an email campaign is created, but they are one of the biggest factors in an email’s success. There is just no single rule, tactic or word that works every time. Best practices sometimes fail and A/B testing is flawed by the time variable when a test is repeated or rolled out.

Why is this?

In simplest terms, being original keeps your subscribers on their toes and can spark in-actives into life. But if every subject line you write is surprising and original, your subscribers catch on and that lack of clarity has a negative effect.

So the key is originality in moderation. But how much originality and how much moderation? Email marketers are not very originalWe analysed half a billion sent messages from 15 of our largest clients across multiple industries to see what they could find. Each subject line was categorized as unoriginal and original – original being a subject line that contained at least one word the sender had never used before. You might think that with such a conservative definition for originality most marketing emails would be classified as original, but as the pie chart shows, less than a third were classified as original.

Original 28.5%

Unoriginal 71.5%  

Original subject lines boost click rates

So what effect does originality (or unoriginality) have on open and click rates?

The results are below:

Unique Click Rate – Unoriginal (2.07%) Original (2.77%)

Unique Open Rate – Unoriginal (14.65%) Original (15.79%)

While we only see a modest increase in open rates when using original words, we see a significant lift – 34% – in the unique click rate.

What’s happening?

Using new and original subject lines trigger an entirely different subset of subscribers to open your emails. Many occasional or non-openers take a chance and open your email because they don’t recognize it from the subject line – “Oh, this doesn’t look like the weekly newsletter I usually avoid”.

We also know through tracking open reach that an open from an occasional or non-opener is much more likely to produce a click in an email, so the click rate goes up.This also explains why the open rate does not increase as much as the click rate because the opposite behaviour is true of regular, multiple openers. The subscriber who diligently opens every weekly newsletter might miss this one if it’s not labelled as such. But that’s okay, because they will just open the next one.

Originality is relative

Defining originality depends on your current email strategy, previous subject lines and on what is happening in your subscribers’ inbox. Using a word once a year might be deemed unoriginal for a monthly newsletter but very rare for a daily deals send.

When everyone in the industry is following the same rules, don’t just follow blindly (never use ‘free’ is a classic example). The specific combination of an original word and your list is what’s important. So define your originality and next time you want to reactivate your in-actives or boost your clicks, get out of your comfort zone and try something new.

Five quick tips for finding original subject line words

Run a quick word frequency analysis of your own subject lines to see which words you use most and which you never use.

Use a thesaurus, it’s a writer’s best friend and can instantly give you dozens of new ways to say the same thing

Take inspiration from elsewhere – we often try and use a Word of the Day in our subject lines to trigger a chain of creativity (e.g. Enjoy a peculiar 21% saving).

Use a dictionary definition of a word, instead of the word itself (e.g. look at all the potential original words found in the dictionary definition of Sale (noun) – an event at which goods are sold at reduced prices, usually to clear old stocks)

Try the subject line tool Touchstone to predict the performance of your original subject lines before you click send. It gives you word recommendations, too.

Last updated: Jan 18, 2015  admin

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