They Laughed When I Used This Subject Line Tactic, But Then I Sent The Email…
by Jordie van Rijn last updated on 0

They Laughed When I Used This Subject Line Tactic, But Then I Sent The Email…

We would all like an intriguing way to get your email converting again – and again – and again. The easiest, hardest best way to go around this? It is not what you might think. It is not producing what the recipient wants, it is not being relevant. That is only a part of the equation. It is presenting it in the way that makes them want to want it. We are emailing a brain and perception is a big part of the message.

How to create an itch and scratch it at the same time? A proven tactic in your emails and subject lines is to appeal to the curiosity of your readers. It seems hard, but luckily, man is curious by nature. We want to discover. Find something new and improved. We want to know about things that seem interesting.

To increase open rates and conversion rates, we need to write compelling subject lines that will have your recipient wanting to open. So one of the email subject line weapons of choice is Curiosity.

Curiosity based subject lines look like….

On the topic of curiosity, I used to think along the lines of “I’ll know it when I see it.” But that doesn’t work if you are writing subject lines and want to add a dash of curiosity power!

If you look for the definition of curiosity you will end up with something along the lines of “the eager pursuit and recognition of new information and experiences”. Most people think about curiosity when something strange, fascinating, bizarre, unexpected, or challenging is presented ­- then they’ll be intrigued. Curiosity tickles.

Intrigue the reader first, then take that primary interest all the way down the road. Provide the means for the audience to satisfy their curiosity…  and turn it into a conversion.

So let’s look at a curiosity pattern: the Question

Curiosity pattern one: the Question

Asking questions is a very compelling way to stimulate Curiosity and elicit an action. From childhood we are trained to answer questions. Your mother might have hit you over the head and say: “Pay attention, I asked you a question!” A good question is a strong path to attention. This is even more true when writing subject lines.

What are some of the mind-blowing facts people don’t know about Curiosity?

The king of subject line questions is Quora. If you don’t know what it is, Quora is a platform that allows people to ask questions on all types of topics and for them to be answered by a crowd. Below is an overview of mails they sent me. It is amazing that I’d like to know the answers to ALL of these questions.


It’s very subjective, I know, but aren’t you eager to hear why people don’t like Nickelback? That question alone sounds like entertainment value in and of itself.  Or, how to psychologically destroy enemies? Good things to know while building an Evil empire.

Maybe they do target their emails very well and above list is a reflection of my personality….. I do hope so, it is a pretty fun list.  🙂

Questions like the ones above signal in the topic. They let you have a taste of the answer that will be given. You don’t know the answer yet, but at least you have an expectation of what is coming. This is what is known as a knowledge gap, more about that later.

When to use curiosity? There are special occasions when using Curiosity is especially fitting:

  • Inform subscribers of interesting info that they otherwise would not have looked at.
  • When they have been inactive and the trick is to re-engage / activate them.
  • When you are introducing something new
  • When it really is a secret / exclusive (for instance information that you would need to log in for)
  • When people will receive a surprise or gift later on.
  • When people are benefit driven and would like to know how to get that benefit. For example: “How we reached X, without doing Y”

Questions are the Swiss army knife of a valueble discovery. Use them to find value and curiosity that you can than turn into different subject lines. For instance with the next tactic….

Remove a key element from your subject line

The trick to writing a subject line that sparks Curiosity is to not tell the whole story. If everything is spelled out  from the start, there is nothing left to be uncertain or curious about. Nothing left to mystery.

Compare these two subject lines:
1. Get 10% off of all products
2. Get 10% off of something

The first subject line “All products” has more value from a calculative and clarity point of view. Discount on all products is more than discount on something, right?

But…. in subject line 2 “something” suggests an unveiling of sorts. It has the implication of a Call-to-Action. Notice the subtle linguistic mechanisms there. I purposely replaced all products with something, not some products.

They laughed when I used this subject line tactic, but when I sent the email…


John Caples, the famous copywriter and advertising pioneer, wrote this classic ad above. It would still work today and is considered one of the very best Ads of its time (1926 mind you!). John has some additional wisdom to add about using Curiosity:

“Avoid headlines that merely provoke curiosity. Curiosity combined with news or self-interest is an excellent aid to the pulling power of your headline, but curiosity by itself is seldom enough.

This fundamental rule is violated more often than any other. Every issue of every magazine and newspaper contains advertising headlines that attempt to sell the reader through curiosity alone.”

Tips and a precaution

Like John Caples said, curiosity by itself is seldom enough. In modern days we might call that “clickbait”. People don’t like to feel betrayed or tricked, which is why every sender should watch out not to abuse Curiosity.

Personally I was pretty disappointed by an email subject line: “[product feature] and why Scrooge McDuck doesn’t wear pants.” The email didn’t really go into the rationale behind Scrooge not wearing pants (but he does wear a full body swimming suit – so i am still wondering why). It leaves you hanging.

It is OK to keep your subject line more mysterious, if you know your audience starts off super interested (fans), context makes up for lack of information (because they know your brand well).

Only make bold statements or use curiosity if you can deliver. This is why a subject line like: “These are simply the best!” can be such a let-down.

Anticipate how your readers will fill in the blanks

A final word, if you want your readers to truly be curios, you need to make sure that they don’t think they know the answer to your brain-teaser. This is why overused formats or questions they can answer by themselves aren’t effective. They need to have that discomforting notion of ambiguity and uncertainty for just short period for in to muster real impact.

Curious for more examples of curiosity infused subject lines? I have summed up the most interesting ones in my email subject line pattern archive. They have imaginative names like the Dotted cliff-hanger, Knowledge gap signal and Mystery gift. Can you think of any more interesting headlines? Share in the comments beloW

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