How to Write Effective Email Subject Lines

As of this morning, my Gmail account officially has 2,316 unread messages. Why such a mess? Aside from unlimited storage and the fact that Facebook sends an email for every tiny activity, my inbox has spiraled out of control because I don’t feel compelled to open the majority of messages that come my way.

This is where the importance of subject lines comes into play.

When you’re sending any type of email marketing piece, be it a newsletter or promotion, pay special attention to your subject line. Too often, this critical piece of copy is merely an afterthought. In reality, the subject is critical because it serves as your only chance to convince readers to open the message. If your reader doesn’t see value from the subject line, finds it boring, or thinks that your message is nothing but a big can of spam, all that time invested in creating an awesome email is for naught.

Considering that the number of marketing emails is exponentially increasing, it becomes that much more important for your message to stand out from the crowd. Take a look at some foundational best practices in increasing the effectiveness of your subject lines:

Your subject line should preview the email content. Your subject line needs to tell readers what’s inside in a very limited number of characters. The subject should nicely summarize the main point of the message, whether it’s an announcement or a special offer. No puffery needed here—simply tell your customers what they’re about to read so they can decide if it’s worth their time.

Don’t make it too salesy or spammy. Watch out for being “overly enthusiastic” when you’re writing a subject line. For example, don’t use caps (indicates yelling), exclamation points, or words like “free” or “act immediately.” First, this will remind readers of the thousands of other sales emails they’ve received, and secondly, it highly increases your chances of finding your email in the junk folder. Here’s one of my favorites of awfulness: “BEST DISCOUNT EVER – 30% OFF TODAY ONLY!” (No idea what they were selling, what the discount was on, or why they’re yelling at me to read further.)

Cater your subject line to the type of message you’re sending. Your subject line should depend on the tone of the message content. If you’re sending out a promotion, go ahead and tell your readers in the subject line about it. If you’re sending out a newsletter filled with helpful content, give readers a summary of what’s inside. In other words, base your subject line on what type of response you want from recipients.

Tell your customers why they should open the email. Place yourself in your readers’ shoes and ask why they would want to read your message. Practicing this exercise allows you to pin down the most compelling reason for customers to open your email. This reason should then morph into your subject line. Is there a helpful article on how to best use your product? Is it an alert to look into one’s account?

Keep it between 35-50 characters in length. Different email programs and different user settings determine how much of your subject line will appear in an inbox. Thus, keep it concise and place the compelling reason to open at the beginning—it makes a big difference.

It’s pretty clear that investing adequate time and consideration into your subject line is a necessary practice in helping your emails be delivered and opened by your target audience. One important rule of thumb is to write the content of your email before writing the subject line—this allows you to capture the essence of the message in a concise and persuasive manner.