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Boost Email Open Rates: 6 Subject Line Tips

Boost Email Open Rates: 6 Subject Line Tips

A strong case can be made that the most overlooked email element – the subject line – is actually the most important. After all, if readers aren’t tempted to open your email in the first place, nothing else really matters. So if you want to increase your email conversions, you have to start with your opens – and that means mastering your subject line. Here’s how.

1. Keep It Short
Today’s readers skim content, especially when they’re on mobile devices. Cater to their habits by keeping your subject length in check. Studies have shown that shorter subject lines have higher open rates. The exact number of optimal characters is open to debate, but 35-55 seems to be the sweet spot. However an interesting study from Return Path determined that while most email subject lines are between 41 and 50 characters, subject lines between 61 and 70 characters had the highest average read rate.
Email Subject Line Open Rates

Whatever the optimal character count, it’s safe to say that shorter is better when it comes to subject lines. And because the average mobile device shows just 25-30 characters of your subject line, it’s also a good idea to front-load your most impactful messaging, including CTAs.

2. Be Descriptive
Studies by MailChimp have found that the top performing email subject lines describe the subject of your email. This may sound a bit boring, but it’s actually a blessing. Composing straightforward subject lines can be far less time consuming than creating clever ones.

That said, there’s no secret formula for the perfect subject line – and clever messaging can work in some cases. In the end, it’s all about knowing your brand and your audience. Both will dictate your subject line messaging strategy. Need help getting started? Return Path has identified 10 common subject line types to consider.  According to their findings, “Urgency” subject lines appear to perform best, followed by “Benefit” and “Command.” While they may work on social networks, “Clickbait” subject lines fare poorly as email subject lines.

In case you need to use one urgently, here are the top performing “Urgency” keywords according to Return Path:

  • expire
  • expiring
  • extended
  • hurry
  • last chance
  • limited time
  • now
  • running out
  • still time

3. Get Personal
Today’s email subject lines can be highly personalized. And it’s no surprise that people enjoy messaging uniquely tailored to them. So consider adding recipient names within your subject lines. This isn’t merely an intuitive thing to do, studies have found that emails with personalized subject lines are almost 30% more likely to get opened. But keep in mind that the personalization effect varies across industries, so there are no guarantees.
Personalized Email Subject Lines

One final note on subject line personalization: Save it for the emails you really need more eyes on. Just like anything else, overdoing personalization can reduce its effectiveness.

4. Remember Your "Second Subject Line"
Believe it or not, you have a second subject line at your disposal. Called a preheader (or snippet text), it’s the short summary text that follows your subject line when your email is viewed from a recipient’s inbox. Text for the preheader is actually pulled from the the first 35 to 140 characters of your email and then displayed beside or under the subject line (depending on email clients).
Email Preheader Copy

Your preheader can be an amazing tool, so don’t waste it! Use it as a second subject line to capture attention and encourage action. Consider personalizing your preheader messaging to increase open rates. You can also include a CTA if it pairs well with the subject line.

Above all, be careful that administrative elements aren’t pulled into your preheater. These unfortunate passengers include unsubscribe links or the dreaded “Having trouble viewing this email?” Place these at the bottom of your email instead.

5. Consider Using ???
Have you recently received a branded email or two with an emoji in the subject line? That’s because emojis are not only cute, they’re possibly email boosters as well. According to at least one article, brands using emojis in their subject lines have experienced significant increases in their unique open rates. You should probably take this with a grain of salt, however. Right now the use of emojis in subject lines is still a good way to stand out in crowded inboxes, but once the practice becomes widespread this is likely to change.
Emojis in Email Subject Lines

If you do choose to use an emoji in your subject line, consider the tone (are quirky symbols appropriate?) and your audience (will they find a heart engaging or off-putting?). You should also test to make sure your emojis render properly on different mobile devices and email clients. Otherwise, instead of ?your subscribers will see ▢. And that’s ? There’s also the issue of spam to consider. While there’s no widespread evidence that using emojis in your subject lines will get your emails relegated to the dreaded spam filter, it’s undeniable that spam filters often contain many emails with emojis - both animated and non-animated. That’s because emojis are commonly used by “less-than-reputable” senders. Should brands be worried that emojis will tarnish them because of spammers? It’s a fair question to ask. The answer at this point is no, but it’s certainly a future possibility.

6. Test, Test, Test
Last but certainly not least, test, test, test! As previously mentioned, there’s no secret formula for the perfect email subject line and preheader. The best way to boost your email open rates is to A/B test different lengths and messages to see how they perform. When you do so, make sure to only test two variants at a time. For instance, test a pair of subject lines against each other to discover which one performs better as measured by the open rate. You can then send the top performer to your email list.

You should also test your subject lines and preheaders to ensure they read well across the dozens of different email clients out there. After everything that goes into creating your high-performing messaging, an audience should be able to see it!

Rhythm works with many brands on their email marketing strategies including email content strategy and development, email design, email best practices, performance testing, analytics and more. If you are ready to launch or refine your email marketing strategy, see how Rhythm can help. Connect with us today.