New Standards for Email Subject Lines

By Head of Marketing - Mon, Aug 4-->



A few weeks ago, Founderwas caught off guard when asked about subject lines at eduWeb. I don’t fault him. Subject lines are tricky - you’re got a minimal amount of characters to convince someone that your email deserves their attention.

Fortunatelya study was released a month ago by AlchemyWorx which gives us some insight on how to do subject lines better. It tested aspects which email marketers had always assumed to be true and returned some surprising results. They use the concept of click-to-open rates, or click-through rates which are calculated against emails that are OPENED, rather than emails that are DELIVERED. Many experts believe this to be a more accurate assessment of the effectiveness of the message.

  • Shorter subject lines generate higher open rates, but lower click-to-open rates
  • Longer subject lines generate higher click-to-open rates
  • Open rates and click-to-open rate curves intersect at about 60-70 characters, whether neither is optimized.

The study concludes that their stats show the impact subject lines have not only on a user’s decision to OPEN a message, but also their decision to INTERACT with the message.

So what does this mean?

  1. Don’t be afraid of long subject lines: Conventional wisdom says that subject lines should be no longer than 50 characters. This came from back in the day when many email clients truncated subjects that were too long. However, most clients today allow up to 100 characters. Don’t be afraid to take advantage of the extra room, since this study clearly shows that medium length subject lines (60-70 characters) get you nowhere.
  2. Longer subject lines work because they provide value: The study hypothesizes that shorter subject garner more open rates because they tend to be misleading - the user isn’t sure what the email is about and opens it to find out more. A longer subject line gives you more space to tell your user what the email is ACTUALLY about! If it’s not relevant to them, they will filter it out but if it is, they are much more likely to take your call to action.
  3. If you create a track record of providing value for your users, they will be more likely to open a message every time you send. I call this “creating a promise” with my users. A cardinal rule of any email program should be that you will not email users unless it is relevant to them. It’s a long-term strategy where you will eventually prove to them that opening your emails is worthwhile. Your subject line is the first thing they judge you by. Make sure you are adequately communicating the content of your message to them so you are managing their expectations about what they will find upon opening it.

Longer subject lines don’t necessarily correlate with success. Neither do shorter ones. The key is to not worry so much about the length and articulate the content of the message so that your user knows what they are getting when they click on it.

12 Responses to “New Standards for Email Subject Lines”

  1. Says:

    It’s important to remember, too, that you don’t have to do this blindly.

    Split-testing your email with a sample of the audience first will give you an opportunity to see what is working with your particular audience.

  2. Says:

    Great ideas to ponder. I regularly use email with 400 students and have used short/sweet subject lines to appeal to the 18-21 set. Considering reframing the message and subject line.

  3. Says:

    It’s no surprise that tailoring what you say, with concision and precision pays off. I recommend a good book on navigating the world of email: *Bit Literacy: Productivity in the Age of Information and Email Overload* by Mark Hurst is a good place to start. The importance of good writing strategies is an under-rated need for 21st century communications.

  4. Says:

    @Associate Director- you’re absolutely right that testing is always a good idea. You have to be careful when you’re testing for non-recurring pieces though, as the results may not apply.

    @Debra - I always use to think shorter was better too. That’s why I found this research so fascinating.

    @Wrye - I’m not really talking about tailored communications here. I’m talking about using a descriptive subject live, regardless of how much you have segmented you lists. No doubt, segmentation is always good….but its certainly not the ball game.

    • Says:

      This really helps a lot!!!! Thank you!!!

  5. Says:

    Head of Marketing ,
    Thanks for the rapid response. I was speaking from the angle of a university writing instructor, not a marketeer. If we can get university students to understand the value of ‘tailoring’-that is-crafting-a subject line to their professors beyond the woefully inadequate SU lines that I see, I’d guess their “success” rates go up. Sorry if this isn’t the right forum for that sort of comment, I was following Debra’s comment; my first foray at eduGuru…

  6. Says:

    My first thought was that people are probably opening the longer subject lines actually because they can’t see the full line (i.e. hotmail ran out of room to display the whole line or something). I side on caution when deleting, and like to make sure I know the full story before i hit the red x…

    I love your conclusion that longer subject lines get higher click to open rates because they allow users to make a more informed decision about whether the email will actually apply to them … and if it’s true, it’s kind of proof of your next point - that you have to be relevant. Crap mail, crap websites, crap blogs, can get all the hits money can buy - but if they’re crap they won’t be successful. 1,000 hits just equals 1,000 people who now know you were crap (and maybe didn’t know until now).

  7. Says:

    It seems quite logical when you think about it.

    The subject line is the one place you have to educate your readers regarding what comes next. An informed reader would be far more likely to click through if the material is relevant. In that respect it doesn’t matter whether the line is long or short as long as it communicates the intent. If it is vague I’m far more likely to assume it is spam.

    As Wrye mentions this applies as much to individual emails as it does to bulk e-mails. I’m far more likely to ignore a blank or obtuse subject line than one that gives me some insight. If I could train my clients to write something more descriptive than “the Web site” (which one?) I’d be thrilled.

  8. Says:

    It might be weird but I am not in the favor of email marketing so I have no concerns with that. In general I always like to write a descriptive and meaningful subject because it always tell the story. I have to send email often to my customers so most of time, I send them email with more detailed subject fields.

  9. Says:

    @adhs - you’re not in favor of something that produces higher ROI than pretty much any other form of marketing out there? If you’re sending emails to cusomters, aren’t you DOING email marketing?

  10. Says:

    Great tips and enjoyed reading the comments too. In a world proliferated by SPAM, the challenge to avoid “spammy” subject lines is ever apparent, whether that be technically spammy or “human perceived spammy”.

  11. Says:

    As a travel agent, I communicate via email with new and excising clients.
    I have always thought of email as a conversation. And I try to keep them business like.
    Recently a new customer complained about the email I sent her.
    So, I am interested to know there are any standards for business email.
    I thought my email was acceptable, but my client did not.

    I look foreword to your advise, Loris