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Subject Line Benchmarks

Author's avatar By Kim Greenop-Gadsby 08 Nov, 2017
Essential Essential topic

Chart of the Day: How Length and Personalization Impact Email

The Email Urban Legend

I'm not talking about those awful email chain letters from the 1990s.

Scared of Email Urban Legends

I'm talking about "keep your subject line length short". We all have heard this, right? I call this an email urban legend because it had never been correctly tested but it has always been accepted. But is this correct? Should we just accept these email legends?

Always question

It's hard to know what is an email urban legend and what is researched advise. The answer is to always look for research statistics. 10 years ago, short subject lines probably were true, but with a number of different devices available is that still true?


If we look at some authentic research like the chart below, we can see that only 5% of the emails in the research had a subject line count of 1-20. However, these are the best performing with a click-to-open rate of 12.9%. The emails with a character count of 61 and over are only in 21% of the emails but they performed better with a click-to-open rate of 8.9%. The most adopted length is 21-60 character and this was the worst performing at 8.5%.

Subject line testing urban legends

Final thoughts

Being email marketers, we need to fill many diverse roles. This research has shown we are not only investigators but scientists. Now remember my little email geeks, these statistics may be true for this chart, but it may not be true for your customers. Always test, research and experiment.


Author's avatar

By Kim Greenop-Gadsby

I get very excited about all things email because I'm just a #EmailGeekUK. I was born and bred in South Africa and have over 16 years experience in web development and digital marketing. When I'm not being an email geek, I spend my time with my husband, two sons and our menagerie of pets.

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Consumer email inbox behaviour

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