Text-Only Subject Lines That Perform, Now That Gmail Grid View Is History

There's "still time" to optimize your email subject lines! Contributor Tom Sather shares stats on what kind of text drives opens in today's environment.

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A picture may be worth a thousand words, but with Gmail’s latest decision to kill Grid View, we’re back to writing subject lines the old-fashioned way: with textual approaches founded on tried-and-true copywriting methods.

What’s the best length for a subject line? Which headlines are better at driving opens? I recently conducted this research study across thousands of brands to find out the optimal formula.

The Perfect Length For A Subject Line Is…

When it comes to how long a subject line should be, keep a few things in mind.

One, look at the most popular devices and email clients that your subscribers are using to read your messages. This will tell you where your subject line will get truncated.

The number of characters in your subject line in and of itself has relatively little to do with whether or not your email is opened. In fact, research shows that there’s nearly no correlation whatsoever.

Out of the nearly 3 million subject lines looked at, a quarter of them were between 41 and 50 characters long, and were read at the same rate as those with extremely short subject lines (0 to 10 characters) or slightly longer subject lines (71 to 90). Subject lines between 61 and 70 characters were read the most with a “read” rate of 17%.

Does the length of a subject line matter then? Absolutely, but just not in the way you probably think it does.

Since over half of all emails are read on mobile phones today, it’s important to consider the device your audience is using to read your messages, and how many characters are displayed before the subject line is truncated. Front-load the keywords and call to action in the beginning of the subject line in case of truncation.

No doubt, marketers will be revising their playbook on this as well, as usage of wearables grows. Marketers will only have 12 to 20 characters to play with on the Apple Watch before it truncates the subject line.

return path subject line length

Keyword Impact On Email Opens

Looking at the most common subject line headline types across 3,000 retailers showed what’s working today and what isn’t. In this study, I categorized the subject lines into a few different types: Benefit, Command, How-To, News, Personal, Reason-Why, Urgency, and Discount. For fun, I also looked at how effective common clickbait headlines were in email.

Urgent subject lines performed the best. People opened emails with subject lines using the keywords “still time” 16% more than average. Other urgency-type keywords that saw a boost in opens included “Limited time” (+3%), “expiring” (+1.6%), and “last chance” (+1%). Keywords  like “running out” and “extended,” however, had a negative impact on opens, resulting in a 3% decline in opens compared with the average rate.

return path subject lines urgency keywordsCommand subject lines were also successful, depending on the keyword chosen. Subject lines telling people to “register” had an average open rate of 24% with that keyword influencing that action by +9%. On the other hand, subject lines with the word “download” had an average open rate of 25%, but that keyword only influenced the read rate by +0.3%.

One Weird Shocking Secret Of Subject Lines You Must Know

You’ve probably seen headlines and subject lines similar to the above. They’re vague and appeal to our curiosity. When it comes to promotional emails, however, they’re just not effective.

Using “get rid of” had a slight influence on whether or not the email was read (+0.8%), but subject lines containing that phrase had a below average read rate of 5%. Subject lines containing “What You Need to Know …” — a phrase I’ve used before — also saw a slight uplift of +0.06% with an average read rate of 11%.

Employing “secret of …” had an extremely negative impact on read rates, dropping the read rate by -9%. While these phrases may be too much for us to resist on Facebook or news feeds, they are likely out of context in our inbox. We need that weird or heartwarming image to push us over the edge, right?

There’s “Still Time” To Optimize Your Subject Lines!

Keep these concepts in mind for your subject line testing strategy:

  1. Know your audience. Brands like ThinkGeek and Moosejaw, for instance, know their audience well enough to know that humor is effective at driving opens. Cost-conscious consumers respond better to discounts than affluent consumers, for example. Knowing your audience will provide the foundation for future subject line testing (and any other marketing activity for that matter).
  2. Ditch vague subject lines. Instead, focus on urgent, command-driven subject lines to get your subscribers to open your emails. Vague subject lines can work (Obama’s use of “Hey” raised millions), but don’t overdo it. The curiosity factor will quickly wane.
  3. Order matters. Challenge yourself to choose two to three words to convey the content of your email, and then place them at the beginning of the subject line. Consumers are reading messages on multiple devices today, so keep truncation in mind.
  4. Steal from competitors. Using a competitive intelligence tool, look at the subscriber overlap you have with your competitors and see what subject lines are working — and those that aren’t — and try them out on your subscribers.

As they say, “your mileage may vary.” Subject line optimization is both an art and a science, and requires patience and a lot of testing, but the results are well worth it.

Opinions expressed in this article are those of the guest author and not necessarily MarTech. Staff authors are listed here.

About the author

Tom Sather
Tom Sather is Return Path’s senior director of email research. Tom uses his knowledge of ISPs, spam filters and deliverability rules to advise marketers on how to get their email delivered to the inbox. He began his Return Path career as an email deliverability consultant working with top-brand clients like eBay, MySpace, IBM and Twitter.

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