Substack comes up in nearly every conversation about starting an author newsletter, usually as a default suggestion rather than a considered choice. "How it works" and "whether you should use it" are actually two separate questions, and answering the first one clearly makes the second much easier to think through.

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How Substack Actually Works

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Substack combines three things into one platform: a publishing tool, an email delivery system, and a payment layer, according to Hootsuite's detailed breakdown of the platform. Writing and publishing is free with no subscriber cap, whether you have ten readers or a hundred thousand. Substack only takes a cut once you turn on paid subscriptions: 10 percent of subscription revenue, on top of standard Stripe payment processing fees, which together bring the real cost closer to 13 to 16 percent of what a paying subscriber sends you. If you never charge for anything, Substack costs nothing.

Beyond the newsletter itself, Substack has grown into a small ecosystem: Notes, a short-form social feed; a recommendation network where other writers can point their readers toward your publication; and support for podcasts and video alongside text. That network is the part most often cited as the platform's real differentiator, since it can put your work in front of readers who were never on your list to begin with.

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What You Get for the 10 Percent

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For an author starting completely from zero, that discovery layer has real value. A new publication with no existing audience can still get found through recommendations and the app's discovery feed, something a standalone email tool simply does not offer on its own. Author and illustrator Austin Kleon runs his long-running weekly newsletter on Substack, which shows the platform works even for an established, non-fiction-adjacent voice who could easily run infrastructure elsewhere.

That discovery matters more given how newsletters actually fit into people's reading habits. Pew Research Center found that 35 percent of college graduates get news from email newsletters at least sometimes, compared with 25 percent of those with a high school education or less, a reminder that newsletters already reach a meaningfully engaged, literate audience before you add any platform-specific growth tools on top.

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Where Substack Falls Short for Authors With an Existing List

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The trade-offs show up most clearly once an author already has an audience elsewhere. Customization is limited compared to dedicated email tools, and the built-in analytics are fairly basic. The 10 percent fee, which barely registers for a small or free list, becomes a real cost once a paid tier grows: at a few thousand dollars a month in subscription revenue, that percentage often exceeds what a flat-fee platform would charge for the same audience. Your free and paid subscriber list is exportable, but the paid billing relationships and the recommendation network itself are not something you can simply carry over if you decide to move.

None of this makes Substack a bad choice. It means the decision depends heavily on where you are starting from. Our guide on how to start an author newsletter covers the format and cadence decisions that matter regardless of which platform you land on.

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So Should It Replace Your Existing Newsletter?

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If you are starting from zero and want built-in discovery without paying for growth some other way, Substack is a reasonable starting point. If you already have an established list on another platform and a following that finds you without relying on someone else's recommendation engine, switching mainly for Substack's discovery tools is a weaker argument, especially once a paid tier starts generating real revenue.

What matters more than the platform itself is what you actually do with it. The Ehrenberg-Bass Institute for Marketing Science has studied what keeps an audience's attention over time, and the underlying lesson, that consistency and a clear voice matter more than any single tool, applies here regardless of which platform sends your emails. Our post on author newsletter examples worth stealing from breaks down real newsletters, including one built on Substack, that succeed because of format and consistency rather than the platform underneath them.

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Keep Your Voice the Constant, Whatever Platform You Choose

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Whichever tool you end up using, the writing inside it is what actually keeps readers subscribed. Want your newsletter to sound like you no matter which platform it lives on? Creating Authentic Content in the Age of AI shows you how to build a consistent, genuine voice across your content.

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Where Podcast Guesting Fits In

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If podcast guesting is part of how you grow your audience, the newsletter signup you send listeners to matters more than which platform hosts it. Download the free Mic to Money ebook to learn how to turn appearances into a repeatable pipeline of subscribers. For the fuller picture of how a newsletter fits into a complete marketing plan, our book marketing ideas guide covers the rest.

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FAQ

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Is Substack really free to use? Yes, for publishing and growing a free list. The 10 percent fee only applies once you turn on paid subscriptions.

Can I move my list off Substack later if I change my mind? Your email list itself is exportable. Paid subscriber billing relationships and the recommendation network are not something you can carry over cleanly, so switching later takes real work.

Does Substack's discovery network actually work for authors? It can, particularly for authors with no existing audience. Its value shrinks for authors who already have an established list and following elsewhere.

Should I move my newsletter to Substack just because other authors use it? No. The right platform depends on where your audience already is, how you plan to monetize, and how much customization you actually need, not on what other authors happen to use.

Ready to decide whether Substack fits your situation instead of guessing based on what everyone else is using? Weigh your current audience size and monetization plans against the 10 percent fee before making the switch.

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