Email marketing has become intertwined with our daily routine. Morning, afternoon and night, you can count on a company emailing you their latest product sales or announcements. While email marketing has become a top revenue-producer for brands across the world, it can be hard to stand out.

In 2015, 205 billion emails were sent per day. In 2018, that number is projected to climb 37% to 281 billion emails sent per day. As inboxes get more crowded, it gets harder to convince customers to care about what your email has to say.

Email subject lines should be designed to make a statement, one that makes the user stop, think and wonder what the email is about. But using a component like curiosity too often in the subject line can make your subscribers become numb to your playful charm and hurt your overall open rates.

While curiosity is one of the most successful methods to get people to open and engage with your email, every good subject line should have at least one of these eight elements: self-interest, curiosity, offer, urgency/scarcity, humanity, news or social proof.

SELF-INTEREST

To produce the best results, you should be using these subject lines most frequently. Typically, they are direct and speak to a specific benefit your audience will gain by opening the email. Self-interest subject lines also hint at clues about your email’s body content.

CURIOSITY

These types of subject lines work for the opposite reason that curiosity-based ones do. These pique the interest of subscribers because they don’t give away too much information, generating more opens. Be wary of how often you use these, though, because they can quickly become boring and get off target.

OFFER

Most people are the same: they like to buy things, and even more, like to get things for free. Your email list will be interested in things you are selling or giving away, so directly say that in your subject line and you are sure to produce higher open rates and sales.

URGENCY / SCARCITY

This is the most powerful subject line you have in your arsenal. Using urgency and scarcity communicates to readers that they must act now, but similarly to curiosity-based subject lines, too many of these can cause list exhaustion. Use these truthfully and sparingly, like when there’s a deadline, limited quantity or limited availability on a product or service.

HUMANITY

Every company relies on people to keep it running. Remind your email list that there are real people who create the products and coordinate services. Appeal to their humanity for attention, tell them thank you or communicate a story that means a lot to you and your brand in the subject line.

NEWS

Inform your audience about new developments in your field or big (exciting!) things that are happening in your company. This will create a relationship of trust and build authority that compels your subscribers to open your emails. Combined with curiosity, these subject lines are very powerful.

SOCIAL PROOF

Humans tend to make decisions after looking at the behavior of others in a similar situation. Leverage this in your email subject lines by highlighting individual success stories, familiar names or displaying how many people already use your product or service.

STORY

Everyone likes a good story. Teasing a story in the subject line of an email will pique curiosity while also highlighting a benefit. Open rates will soar as you grab the audience’s attention.

Here are 12 foolproof email headlines that will work every time:

Here is a Method That is Helping [world class example] to [blank] – Social proof

Savvy|Smart|Stylish People Do XYZ – Curiosity

Why I [blank] (And Maybe You Should Too) – Humanity

[Do something] like [world-class example] – Self-Interest

The [desired result] That [world class example] Is Talking About – Curiosity

Join [impressive number] of Your Peers that [take desired action] – Social proof

[desired result] Like A [desired group or person] – Self-Interest

How [impressive number] Got [desired result] in [time period] – Social proof

Like [world class example] You Can [desired result] – Self-Interest

[world class example] Reveals Ways To [desired result] – Curiosity

Why [impressive number] of People are [taking desired action] – Social proof

A Simple Way To [desired result] That Works For [desired group/person] – Curiosity

While some headlines might be more effective, it’s always good practice to have each of the eight element categories sufficiently represented throughout your email marketing strategy.