In MarketingSherpa’s blog post about this, they quote Tom Sather, Senior Director of Research, Return Path: “… ‘average read rate’ is defined as ‘the percentage of email recipients who have marked your email as ‘Read’ in their email client [i.e. email reader] — typically thought of as more accurate than open rate, since read rate is not dependent on image downloads.’” The data says:
- The most frequent length of characters is 41 to 50 characters. One reason this is considered a best practice is that many email readers and browsers cut off subject lines longer than this, and mobile devices are even more limiting.
- But note that subject lines of 61 to 70 characters had a 17% average read rate, the highest of any length.
Do you know your email recipients well enough to know how they read your emails? If you do, and if they’re reading email mostly on mobile devices, then double down on shorter subject lines. For further reading, here are 10 best practices for mobile-friendly emails.
So, the takeaway is: Shorter is usually better, but if you’ve got a longer subject line that you like, test it. Front-load the key words so you’re sure they get seen.
Every email send is unique, and your mileage may well vary.
One additional way to learn how to write compelling subject lines is to take a look at what NOT to do. Sounds like an Act-On blog post, right? It was. Read 8 terrible email subject lines.
2. Keep your subject lines on topic, and not misleading.
Remember that your subject line is setting expectations for the content of your email. Nobody likes bait-and-switch. You want to ensure that your subject lines get your message across succinctly, without misleading the recipient. If a recipient thinks a subject line is misleading, they could feel that they’ve been duped. This could get your email marked as spam by an angry reader (they could be a former customer, or could have just had a bad day). People sometimes make this mistake when they’re riffing on a current news topic or trying to be funny. Don’t sacrifice clarity for cleverness.
And don’t use RE: or FW: to make it look like the email is part of a string the recipient has been previously involved with.
3. Personalization can be key.
In Q1 2015, Experian performed a custom analysis for MarketingSherpa based on Experian Marketing Services’ quarterly email benchmark analysis from client brands within the United States and Canada (which relies on clients that opt in to participate in this study). The results: