Email subject lines

Every marketer who uses email wants to get the highest possible open rate. At Resources Online, we’ve found that the right subject line can significantly improve email open rates. For some of our email campaigns, it can make as much as a 5-percent difference! We do a couple of things to help ensure that the maximum number of our subscribers open and read our emails.

Test multiple subject lines for each newsletter

Testing is the single most important thing we do to optimize subject lines. We always test at least two—and sometimes as many as 12—different subject lines for each newsletter. All of the debate and subjective opinions about subject lines goes away in the face of hard data—seeing what your subscribers actually respond to. Try this simple testing process:

  1. Draft a few of your best subject lines.
  2. Have everyone on your team make their best guess as to which subject line will win. This friendly competition can sharpen creativity for future subject lines.
  3. Send an actual newsletter to a portion of your subscriber base with each subject line. You want at least 200 to 300 opens for a meaningful sample size. For example, if your open rate is 25 percent, send out about 1,000 emails for each subject line.
  4. Wait a few hours (or even until the next day), and then look at the email open rates for each subject line.
  5. Pick the winner, and send the winning subject line to the remainder of your subscriber base.
  6. Write down the results, and learn from them!

Use words that help. Avoid words that hurt. 

  • Questions are almost always better than statements. People are naturally curious, and when you ask a question they want to know the answer.
  • Appeal to people’s sense of competition or comparison. Questions like, “Who is funnier, Jennifer Lawrence or President Obama?” or “iPhone vs. Windows Phone—who wins?” immediately pique interest.
  • Avoid the hard sell, particularly with words and phrases like free, help, percent off, and reminder. Nobody likes a nag. And spam filters don’t like these words either, so your email might not even be seen if you use them. Of course, if you do have a compelling offer that is, in fact, free, go nuts. The offer will speak for itself as long as you mention it in the subject line (but perhaps use freebie instead of free).

Consider these other tips

  • Be as specific as possible. Don’t use a coy subject line to make your subscribers guess what’s in the email.
  • In general, keep the text of the line short—50 characters or fewer.
  • Don’t repeat your subject line in subsequent newsletters.
  • Try referencing current events, such as an upcoming holiday, the Oscars, or the Super Bowl.
  • Edit the subject line to make it easy to scan in a crowded Inbox, and eliminate unnecessary words. Be pithy.
  • Put yourself in the recipient’s place—what would your reaction be to this email subject line?

Email can be a powerful marketing tool, but it’s one that you have to avoid over using. So, it’s worth spending the extra time to perfect your subject line (and your email content) to maximize the value of each mailing.