4 Top Tips for Optimizing Subject Lines (Yes, They Still Matter!)

Let’s face it – there’s nothing sexy about email subject lines.

While some might argue that there’s nothing sexy about email (and I would strongly disagree), there are certainly hotter and far more exciting topics to email marketers these days, like Gmail’s Tabs and responsive design for mobile. In fact, if I use Google Trends to track search term activity over the past 90 days for “responsive design,” “gmail tabs” and “subject lines,” the average for “responsive design” is 875% greater than the average for subject lines. Even though Gmail only released the tabs feature in late July, the average for tabs search term activity is still 163% greater than searches for subject lines.

It’s not surprising that many marketers will spend far more time obsessing over “shinier” aspects of their email programs, like adding video to their email creative, incorporating dynamic content or testing the perfect images. These are all great tactics and worthy of time and resources, but not at the expense of a simple A/B subject line test. Subject lines are the catalyst for email response and engagement. Every action that takes place following a message’s delivery to the inbox can be tied back to your subject lines.

In my opinion, subject lines are the hardest working element of your email program (but often the most ignored). It’s time to pay more attention, and if you’re not testing them, start now. At the very least, keep in mind that with mobile opens now surpassing opens in any other environment,  and the average order value by device showing a higher order rate by mobile phones ($97.39) and tablets ($96.11) when compared to desktops  ($91.86), your subject lines need to work even harder to stand out in multiple environments amongst subscribers’ numerous on-the-go distractions.

Here are four tips for optimizing your subject lines to ensure they are primed to do the heavy-lifting:

  1. Incorporate special characters: This is a great way to stand out in the inbox and use symbols to compliment the purpose of your message. Research also shows that using special characters shouldn’t have a negative impact on your inbox placement rates and can make a measurable improvement in engagement rates, when compared to your other campaigns. However, beware of too much of a good thing. In other words, don’t overuse this tactic and consider using special characters sparingly and only for certain campaigns. It’s also important to match the character with the purpose of the message otherwise you can create confusion or run the risk of desensitizing your subscribers, leading to fatigue. Consider these two recent subject lines I received as part of campaigns from the travel sector. Travelocity used an airplane character for a promotion on flights, while Priceline just used a square box unrelated to the offer. A character showing a car would have been more relevant:

  1. Personalization: 10 years ago, this tactic was all the rage; however whether to use personalization elements can actually be a pretty divisive topic. Not unlike other email marketing practices that have fallen out of favour, spammers have something to do with it. They’ve overused personalization elements (like first and last name), which have caused legitimate brands to stay away from doing anything that seems spammy. However, personalization can make a positive impact on driving engagement and response when it’s used in combination with other data points that are unique to the subscriber. For example, a recent action a subscriber has taken, like browsing your website or making a purchase. Compare these four subject lines; the first two from Ticketmaster and Amazon include my name, but no other personalization elements. The second two have incorporated other data points for greater relevancy (i.e., Netflix is referring to a TV series I have in my queue and British Airways is referring to my club membership):
    • Ticketmaster: Margaret Farmakis, See it Live: Tickets on Sale & Special Offers This Week
    • Amazon: Margaret M. Farmakis: Books Top Rated by Customers
    • Netflix: Margaret, Scandal Season 2 is now on Netflix
    • British Airways: Ms. Farmakis, belonging to the Executive Club now means even more
  2. Frontload: While the standard best practice used to be to keep your subject line length between 30-60 characters to avoid truncation at the various mailbox providers, that isn’t a  hard and fast rule anymore as longer subject lines can be just as effective as shorter ones, and what works really depends on what resonates with your subscribers. For example, we’ve seen newsletter campaigns that are more effective when the headlines of the top stories are listed in the subject line and are as long as 100 characters, while shorter versions using only the newsletter’s name and date have been just as effective.It all comes down to testing, learning what drives a response with your key subscriber segments and continually optimizing, however a good rule of thumb is to frontload your subject lines with the most important information first. This can be especially critical for subscribers viewing email on mobile devices and deciding whether or not they want to save your message for future viewing on a desktop or if they’ll delete it unread. Time-sensitive content, personalization elements and action verbs are all appropriate to feature first.
  3. Quick Action buttons: Gmail has created a way for your subject lines to work even harder. In fact, with Quick Action buttons, they might actually do all of the work for you. This feature, which was announced in May, enables you to include a call-to-action button right in the subject line of your email message so that subscribers can convert without ever opening the email. Quick Action buttons are only available for certain types of messages and you’ll need to register with Google and use schema.org markup. Below are some examples of brands using this feature:



Want more tips for optimizing your email program and standing out from the competition? Check out our on-demand webinar: “The Power of Competitive Insight.”


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