Why Did 'SEO for Esoterics' Beat Broader Headlines? 3 Testing Insights

Test #3 was the most surprising.

Substack A/B Testing: How I Increased Email Open Rates with Better Headlines

Substack recently granted us the ability to test headlines (“A/B Tests”), so you know I've been all over it! What is headline testing? Substack will send a variety of headlines to a portion of your subscribers, and will choose the best-performing one to send to the rest of your subscribers. This means you can maximize your open rates in real time without risking your entire audience on a potentially weak headline. You get actual data on what resonates with your audience, rather than guessing. How many times have you deleted a newsletter in your inbox because the title wasn't relevant to you and your needs in the moment? How many times have you clicked because it intrigued you? This tool helps you figure out what captures people's attention. Click here to read a detailed post about how to test headlines.

Following up on my article about SEO for Esoterics, I wanted to share these headline tests and the results — the third one is actually pretty surprising! Here goes:

Test #1: The Live Event (Urgency Won)

Twice a month, I host a live meetup for paid subscribers. I sent an email out the day of with the Zoom link, and this is the test for the one I hosted on August 18:

• "Live Meetup Tonight!" - 40.0% open rate (6/15) ✅ Winner

• "There are TWO New Moons in Virgo this Year. Highly unusual!" - 33.3% (6/18)

• "New Moon in Virgo Meetup Tonight!" - 26.7% (4/15)

"Live Meetup Tonight!" Brevity is usually your friend when it comes to emails, and this three-word headline delivered just about everything people needed to know. Because such a small pool of people received this test (only 15 people in 1 hour), it’s possible it’s only by chance that “Live Meetup Tonight” did better than “New Moon in Virgo Meetup Tonight,” but in general, it’s been my experience that less is more when it comes to headlines.

Test #2: Astrological Insights (Curiosity Won)

After each live meetup, I send out a text summary of our meeting with insights on the new or full moon and any other topics we discussed. It's usually a hodgepodge of astrological and spiritual insight, intended to be a digital package of wisdom for the reader. Here’s the test I ran for the newsletter I sent after our August 18 meetup:

• "Two New Moons in Virgo: Cosmic Chaos or Perfect Preparation?" - 23.8% (82/345) ✅ Winner

• "New Moon in Virgo August 2025: Double Eclipse Energy Explained" - 24.1% (77/319)

• "August 2025 Astrology: Why Two Virgo New Moons Change Everything" - 23.8% (80/336)

• "September's Eclipse Will Change Everything (But Don't Plan Yet)" - 18.9% (66/349)

Questions in a headline inspire engagement; readers want to know the answer!

New on Substack: A/B testing for headlines, profile customization tools, and livestream updates

Test #3: SEO Tutorial (Niche Specificity Won)

Sometimes I post random tutorials! Here are the results for my newsletter on SEO:

• "SEO for Esoterics (and other writers)" - 21.7% (77/355) ✅ Winner

• "How Do You Optimize a Substack for SEO? 10 Helpful Tips" - 21.5% (69/321)

• "10 SEO Tips for Substack Writers: Optimize Your Newsletter for Discovery" - 20.4% (71/348)

• "Substack SEO Guide: 10 Tips to Make Your Newsletter More Discoverable" - 18.6% (59/318)

The title "SEO for Esoterics" winning was very surprising. As I suggested in the very same newsletter that I sent out for this title test, headlines with broad appeal are fabulous for SEO. In this case, what was fab for SEO ended up not being true for the open rate, and spotlighting my niche audience in the title ended up winning!

What These Tests Taught Me

Test your headlines! This taught me that best practices for SEO might not always be what you need to engage your subscribers; sometimes you need to lean into your niche and not cast the widest net. "SEO for Esoterics" was my working title, and I was sure another, simpler, broader headline would do better. But I was wrong! I'm so glad Substack offers title testing now so we can all see which headlines our readers will like the best.

Will I test headlines for this newsletter? You bet! Here are the three I’m going to try — I’ll update this post on Substack when the results are in :)

• Option A: Substack A/B Testing: How I Increased Email Open Rates with Better Headlines

• Option B: Newsletter Growth for Esoteric Writers: Real Headline Testing Data

• Option C: Why Did 'SEO for Esoterics' Beat Broader Headlines? 3 Testing Insights

UPDATE! The results are in:

Test #4: A/B Testing (Niche Specificity Won AGAIN)

• "Why Did 'SEO for Esoterics' Beat Broader Headlines? 3 Testing Insights" - 24.2% (119/492) ✅ Winner

• "Substack A/B Testing: How I Increased Email Open Rates with Better Headlines" - 24.1% (108/449)

• "Newsletter Growth for Esoteric Writers: Real Headline Testing Data" - 23.1% (102/441)

Once again, phrasing the title as a question worked best for me, and my audience of esoterics appreciate the recognition!

Are you using A/B Testing? Let me know what you think!

With cosmic love,

Annabel

Photo by Lionel HESRY on Unsplash