The science of writing strong email subject lines

How to change your life.

Less than 24 HOURS LEFT.

Ready to quit your job?

We want your feedback.

Say “eff no” to being realistic.

These are just a few subject lines of emails that have hit my inbox and they caught my attention. But why?

The first makes me curious. Do I need to change my life? Could I make it better by whatever they are about to tell me in a single email? 

The second provides a sense of urgency and curiosity. What do I only have 24 HOURS LEFT to do? 

The third asks an interesting question—a yes or no question. If any of their recipients’ answers is “yes”, that will most likely be enough for them to open the email.

The fourth is valuing my opinion. Everybody likes to give their opinion nowadays.

And the fifth presents a controversial statement. Shouldn’t we strive to be realistic? 

Mastering the art of crafting a subject line is critical. If it sucks, nobody will read your emails.

Simple as that.

The types of subject lines

So let’s look at a more complete list of ten different types of subject lines that can capture your audience’s attention.

  1. To the point. Such as “Your order has been processed” or “Your order has shipped”. This is more for a transactional email.
  2. Humorous (“We know you’re procrastinating anyway”)
  3. Shock factor (“I got hit by a bus.”)
  4. Question (“What would YOU do?”)
  5. FOMO (“The countdown begins”)
  6. Pique curiosity (“It was a terrible day”)
  7. Personal with name (“Becca, thanks for signing up!”)
  8. Special offer (“BOGO today only!”)
  9. Sense of urgency (“24 hours left to register”)
  10. Use numbers to indicate a list—implies being thorough (“5 reasons to quit your job”)

How do you know if it worked?

You’ll want to know how to determine if your email subject line did its job, so let’s look at average open rates (how many people opened your email) and click-through rates (when someone clicks on a link within your email).

In general, you should feel pretty good about an average open rate of 20-30% and a click-through rate of 2-5%. Depending on your industry, the averages fluctuate slightly—Mailchimp actually has a GREAT guide on averages in many different industries. See below!

Robin Writers’ real-life examples

Writing this post made me think about the performance of my own subject lines for my newsletter. Here are some that I think are noteworthy:

“Here is how to get more clients”: 32.6% open rate, 3.5% click-through rate

I think this one performed well because the subject line piques some curiosity and is an open loop—and I have also seen a lot of freelancers say that they wanted help on finding more clients. This also impacted the click-through rate since my audience wanted an answer to their question, so they were more inclined to click to my blog post about how to find more clients.

“Propel your content writing skills forward TODAY”: 37.5% open rate, 5.2% click-through rate

I believe this email had a strong open rate because the subject line conveys a message that change can happen immediately—and I wasn’t lying! And the most clicked link was the year of writing prompts I created to accomplish what the subject promised. So this tells me that my message was strong and convincing enough for my audience to want to take action. Success 🙂

“Trader Joe’s is the teacher this week”: 16.7 open rate, 1.4 click-through rate

I think there are a few factors why this newsletter did not perform so well. First, I think my subject line is weak. I thought by mentioning a familiar brand that it would pique interest, but I don’t think the rest of the subject line was compelling enough. And because there was a low open rate, I think that affected the click-through rate for the blog post

If I were to rewrite this subject line, I may write something like, “This is what oatmeal can teach us”, which creates an open loop (what can oatmeal teach us?”) and I think it’s random enough that may pique some curiosity (because what the heck can oatmeal actually teach us?). 

How would you improve all of these subject lines? Comment below!

Even from these three examples, you may see how the subject line alone is so crucial to the success of an email. You could spend so much time crafting the perfect email, but if nobody opens it…then it will never get read 🙁

Now go be a subject line master!

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  1. Hi Becca. I like your first two examples because they tell me exactly what the email is about. I’ve become jaded to sensationalistic subject lines that give no clues and are just trying to make me click and I don’t know if the topic even interests me. Or subject headings that are too negative. I had subscribed to someone’s newsletter who kept putting out negative subject lines that seemed designed to create panic. The final straw was an email titled something like “10 Reasons You will Fail”

    1. Hi Karen, thanks for reading and the feedback! And I totally understand what you mean about the tricky subject lines. I think a lot of readers are catching on to some people’s tricks and how some seem to be more “click bait-y”. But if you joined my newsletter I hope mine come off as genuine! Thanks again for reading and sharing your thoughts 😁

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