And the Best Subject Line Is …

Click to enlarge this infographic from ContactMonkey, or visit this URL to see the rest of the research:

Blank. The best-performing subject line is … blank. Well, not completely blank. The best subject line is “Re:” or “Fw:” for senders who are trying to sell email recipients something, according to ContactMonkey research.
The Toronto-based email tracking software provider cataloged 30 million messages sent from Outlook and Gmail and announced its findings Wednesday.

“Re:” has a 92 percent open rate, closely followed by:

  • Re: Follow Up (90 percent)
  • Re: update (89 percent)
  • Re: Introduction (88 percent)
  • Re: Checking In (87 percent)

At the bottom of the barrel is “The results are in,” with a 7.25 percent open rate.

“The shorter the subject line, the higher [the] chance of your email being opened,” according to the infographic. “Remember: The more basic subject lines often perform best.”

Consumers may be opening these types of emails the most because of how few words show in email clients on smartphones, says Scott Pielsticker, CEO and founder of ContactMonkey.

More advice about subject lines from ContactMonkey includes:

  • Use two words or fewer. “On average, these emails were opened more than twice and have an 80 percent open rate,” according to Wednesday’s announcement. Subject lines with three words or more have an average open rate of 15 percent.
  • Depending on the mobile screen, on which 40 percent of recipients open emails, recipients will see between four and seven words.
  • “When in doubt, use Re:. Don’t bother crafting the perfect subject line. There isn’t one!”
  • Be direct. If marketers want to introduce themselves, use “Introduction” or “intro.”
  • Be demanding. Don’t ask questions, as question marks perform poorly.
  • Don’t use marketing lingo, no matter how “innovative” marketers are—or how filled with “industry secrets” they want to reveal to prospects.

Do these subject lines make sense for all marketers?

Please respond in the comments section below.

Heather Fletcher is senior content editor with Target Marketing.
Related Content
  • Tjpnugent

    I find those high end open rates pretty hard to believe.

  • GloriaND

    Although I agree that “Re:…” and “Fw:..” subject lines will generate higher opens, I think they are also VERY popular with spammers and depending on your target group, you may want to test them first and see if your email gets flagged or not.

  • kklav

    These subject lines are deceptive and I’m sure would be frowned upon by most legal advisers given CANSPAM regulations. The only reason the open rates are so high is because they are afraid it is something important and the only way to know is to open it. Putting Re: implies that someone is responding to something you initiated which is very misleading. Open rates aren’t everything, if the recipient feels like they were tricked into opening something you will do more harm than good.

  • Matt May

    My immediate thought is that it violates CAN-SPAM rule #2: Don’t use deceptive subject lines. The subject line must accurately reflect the content of the message.

    Furthermore, I’d like to see the unsubscribe results and complaints (marking as spam) that goes along with this study. Open rates only tell a small part of the story.

  • Ian Hough

    I’ve never read anything like this before. Is it a joke? A respectable business can’t send mass emails out with “Re:” as a subject line. We leave that to spammers.

  • Patrick McGovern

    Yes, those open rates are very hard to believe, if you assume they’re talking about mass e-casts. But they’re not. It seems the deployments they’re talking about are one-off emails sent by “salespeople,” through Outlook or Gmail (possibly as a follow-up to a phone call or some other contact?). I would definitely not recommend sending out something like a regular e-newsletter with such an uninformative subject line.

  • Andrew Barrett

    Using Re: or Fw: in the subject line in this manner violates misleading subject line requirements in CAN SPAM, and similar laws in non-US countries – particularly Canada and the EU.

  • gilbertdirect

    Those “RE” open rates must be for people REsponding to something else. My gym uses RE in their subject line all the time. I always tell him not to. Is it deceptive? Yes. Does he have a legit business? Yes. But he wants open rates and gets them. Whats awful is at this point after years of his subject lines, we are all conditioned to opening them even with the deceptive subject line

  • Amir

    Sending a “Re:” and making the recipients believe that they are opening an email thread that they were already a part of:

    1. Violates CAN spam/CASL
    2. is unethical
    3 is definitely going to hurt your business in the long run unless you are Jim Gilbert’s trainer.

  • HeatherReporter

    I’m glad to see so many responses!
    Okay. As I’ve mentioned, I’ve asked ContactMonkey to respond to your questions/criticisms. I haven’t heard back from them and they haven’t posted here.
    So I will make a couple comments.
    1. This research from them is only about open rates.
    2. This research is not about consequences, about which many of you have valid concerns. Indeed, in all the best practices articles I’ve written, subject lines are not misleading, not spam, etc. They follow, as noted, best practices.
    3. However, this isn’t the first bit of research to show email recipients have a tendency to follow their own rules. Symbols used to be a no-no in subject lines. See No. 7 here:
    4. I’ll keep an eye out for a study related to the consequences of using these types of subject lines.

  • jamesalexsmith

    Hi Folks! I’m Alex from ContactMonkey. Apologies for not getting back to all of you sooner, it was a long weekend up here in Canada. First off, amazing questions and thank you for starting a discussion. I’ve gone through now to follow up all of your questions personally. The important thing to remember here is that our data is based off of the emails our customers have tracked from either Outlook or Gmail – not an email marketing tool that many of you are used to. Emailing is very different between a salesperson and a marketer. A salesperson is sending individual, personal emails to their prospects throughout the day. They rarely dabble in the mass email space. That might be why the email open rates seem high and that the subject lines themselves aren’t necessarily suitable for mass e campaigns. However, I think the biggest lesson for marketers here is to test out very short and direct email subject lines. Of course while taking CAN Spam/CASL into account.

    Thanks again and all comments and questions are welcome!