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The Psychology of the Subject Line: Why We Click

It is not luck. It is science. How to use cognitive biases to double your open rates.

Andreas Hatlem

Andreas Hatlem

Author

The Psychology of the Subject Line: Why We Click

The subject line is the gatekeeper. It doesn't matter if you used our beautiful React templates or have the best offer in the world—if the subject line fails, the email dies.

At GetMailer, we have analyzed millions of emails sent through our platform. The difference between 15% and 40% open rates isn't usually luck; it's psychology.

The 3-Second Rule

You have 3 seconds to earn a click. We found that the best performers use Curiosity.

1. The Curiosity Gap

Don't give it all away. "Our January Update" is boring. "The one metric we stopped tracking" creates an itch you have to scratch.

2. Loss Aversion

We humans hate losing things. "Your discount expires tonight" works better than "Get a discount." It triggers FOMO (Fear Of Missing Out).

The "Mobile Cutoff"

This is a technical constraint we obsess over. On an iPhone, you only have about 40 characters. We recommend front-loading your keywords. Don't put the punchline at the end.

Stop Guessing: A/B Test It

We built A/B testing into the core of GetMailer because we don't believe in guessing. Test a "Benefit" subject line against a "Fear" subject line. Let our data tell you the winner, then auto-send that to the rest of your list.

It's not magic. It's science.

Subject LinesPsychologyCopywritingOpen RatesA/B TestingMobile

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