# How Newsletter Writers Use A-B Testing Subject Lines to Boost Open Rates

Page: https://stenobird.com/podcast/the-newsletter-podcast-with-fexingo-substack-beehiiv-and-email-newsletter-business-7871729/how-newsletter-writers-use-a-b-testing-subject-lines-to-boost-open-rates
Text version: https://stenobird.com/podcast/the-newsletter-podcast-with-fexingo-substack-beehiiv-and-email-newsletter-business-7871729/how-newsletter-writers-use-a-b-testing-subject-lines-to-boost-open-rates.md
Podcast: [The Newsletter Podcast with Fexingo: Substack, Beehiiv, and Email Newsletter Business](https://stenobird.com/podcast/the-newsletter-podcast-with-fexingo-substack-beehiiv-and-email-newsletter-business-7871729)
Published: 2026-07-07T18:50:28+00:00
Episode link: https://audio.fexingo.com/business/the-newsletter-podcast/episode-0098.mp3
Audio file: https://audio.fexingo.com/business/the-newsletter-podcast/episode-0098.mp3
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Duration seconds: 516

## Resource

In Episode 98 of The Newsletter Podcast, Lucas and Luna dive into the science of A/B testing subject lines for email newsletters. They break down a real-world case from a 200k-subscriber marketing newsletter that tested '5 Growth Hacks' versus '5 Growth Hacks That Actually Worked' and saw a 22% lift in opens. The hosts discuss sample size minimums, statistical significance, and how Beehiiv's built-in A/B testing tool compares to Substack's manual split. They also touch on the psychology of curiosity gaps and the common mistake of testing too many variables at once. Perfect for newsletter writers who want to move from guessing to knowing what drives opens. #ABTesting #SubjectLines #EmailMarketing #OpenRates #NewsletterGrowth #Beehiiv #Substack #MarketingTips #Copywriting #CuriosityGap #DataDriven #EmailNewsletter #FexingoBusiness #BusinessPodcast #Marketing #NewsletterStrategy #ConversionOptimization #ContentMarketing Keep every episode free: buymeacoffee.com/fexingo

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## Transcript

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