Want to write killer subject lines? Steal this prompt.

A reader took my research on email subject lines and created a custom headline maker (and even named it after me!)

šŸ‘‹šŸ» Welcome to Newsletter Examples, where I highlight cool sh*t Iā€™m seeing in newsletters that you can steal for your newsletter.

This week, Iā€™m showing how Mark R. Hinkle of the AIE Network used my insights on effective subject lines to create a powerful headline-generating tool. Reading time: 3 minutes.

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Step 1: Gather inputs

A few years ago, I did an analysis of 750+ email subject lines at The Hustle. It was one of my most engaged threads ever.

Some of The Hustleā€™s winning subject lines (ā€˜20-21)

Among other things, the analysis showed that:

  • Shorter is (almost always) better. The Hustleā€™s best subject lines averaged just 33 characters.

  • Boring isnā€™t always bad. One of the most-clicked emails (55% open rate) was headlined: ā€œHow bitcoin are created.ā€

  • If you help people make money, theyā€™re apt to click.

  • Making declarative statements can also boost opensšŸ‘‡ļøā€¦

Step 2: Create a prompt

Reader Mark Hinkle took that research, including actual winning subject lines from hundreds of A/B tests at The Hustle, and turned it into a ChatGPT prompt to help him write better headlines.

Below is the prompt he came up with:

  • Notice how he provided ChatGPT with a ā€œroleā€ and ā€œobjectiveā€

  • You can use this prompt to improve your headlines (I copy/pasted the prompt here so you wonā€™t have to retype it)

  • Feel free to tweak the prompt based on your own inputs and learnings

Step 3: Save your prompt

Hinkle, author of The AI Enterprise newsletter, one of my go-to AI newsletters, uses PromptDenā€™s PromptForge to save his prompts.

It allows him to replace the variables while preserving the examples he used in the few-shot prompt. ā€œI just click a few buttons, and the prompt is rendered in ChatGPT,ā€ he wrote in his Dec. 3 issue, where he shared this and other secrets from his ā€œAI magicianā€™s toolkit.ā€

Step 4: Create a GPT

But Hinkle took it one step further, codifying the prompt into a CustomGPT.

He basically built an Email Headline Making Machine, which he says works even better than the prompt.

He named it the Brad Wolverton GPT lolā€¦and made a copy available for Newsletter Examples readers (you need a ChatGPT account to access it).

I asked Hinkle how Brad Wolverton GPT has performed for The Artificially Intelligent Enterprise, and he pointed to some impressive open rates (between 60.9% and 64.1%).

Here are some of the winning subject lines and preview text the GPT has come up with:

But even a so-called AI magician doesnā€™t use AI for every headline. In fact, he doesnā€™t use AI headlines at all in AI Tangle, another one of his newsletters, and its open rates are even higher (78% to 88.9%).

Whatā€™s the secret to those open rates?

ā€œThe big advantage,ā€ Hinkle told me, ā€œis my writer.ā€

Hope you enjoyed this weekā€™s examples. Iā€™ll be back next week with a new set!

ā˜®ļø -Brad

P.S. Congrats to readers Juliet Lyall and Ethan Brooks, who guessed where I took that gorgeous pic in the UK with my family. In case youā€™re wondering, it was Oxford.

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