Introduction
Why this book exists
Every newsletter guide I read while I was building mine had the same problem. It told me what a good newsletter looks like once it's already working. Nobody wrote down the part where you have 40 subscribers and no idea if issue six is any better than issue five.
I started two newsletters. AI For Developers went from zero to more than 40,000 subscribers in about a year. The Marketing Newsletter passed 20,000, running on its own domain instead of a Substack subdomain, which is its own decision with its own tradeoffs and I'll get into why later in this book. Neither one grew because I found a secret. They grew because I made a lot of small, correct decisions in a row, and avoided a long list of mistakes that are completely avoidable once someone tells you about them.
This book is that list. Not a theory of what makes newsletters succeed, a checklist of what to actually do, in the order you'll actually need it: before you launch, in your first month, once you have an audience worth protecting, and once you're big enough that growth stops being the hard part and operations becomes the hard part.
I'm writing this in 2026, which matters more than it would have five years ago. The platforms have changed. Substack Notes didn't exist in its current form a few years back and is now the main growth lever for anyone under 10,000 subscribers. Apple's Mail Privacy Protection quietly broke open rate as a trustworthy metric, and most of the growth content still floating around the internet hasn't caught up to that. Beehiiv built an actual ad marketplace into the platform itself. AI changed what "good writing" costs to produce, which changed what it's worth. A book about newsletters written in 2021 is not wrong exactly, it's just describing a market that doesn't fully exist anymore.
How to use this checklist
Read it in order the first time, even the parts that don't apply to you yet. Part Six is about monetization and you might be nowhere near ready to charge anyone for anything, but knowing what the paid tiers look like before you launch changes decisions you make on day one, like which platform you pick and what you promise your first subscribers.
After that, stop reading it front to back. Use it as a reference. Each part ends with a checklist built to be reused, not read once and forgotten. Print them, screenshot them, whatever gets them in front of you again before you hit send. I still use versions of the "before you hit send" checklist myself, and I've been doing this for years now.
One thing this book won't do: tell you there's one right platform, one right posting schedule, or one right way to write a subject line. There isn't. I'll tell you what the tradeoffs actually are and what I'd do given a specific niche, list size, or goal, but the decision is still yours. A newsletter about developer tools and a newsletter about parenting are not going to succeed by following identical playbooks, even though most generic advice is written as if they would.
I'll say it once here so I don't have to keep repeating it: if a chapter's advice doesn't fit your situation, that's not a sign you're doing it wrong. It's a sign the advice was written for someone else's newsletter. Adapt it or skip it. The checklists work the same way, they're a floor, not a contract.
My newsletter journey
I didn't start AI For Developers because I had a grand plan. I started it because I was reading about AI tooling constantly for my own work and writing notes to make sense of it, and at some point it seemed obviously dumb to keep those notes private. The first issues went to a list you could count without a spreadsheet. Growth was slow, unglamorous, and mostly manual: showing up, writing something worth forwarding, telling people it existed.
What changed the trajectory wasn't a viral moment. It was consistency compounding with a topic that had real, growing demand behind it. AI for developers was a real thing people needed help understanding, in real time, and I kept showing up with it. A year in, the list had crossed 40,000. Not because any single issue went viral. Issue after issue, each one earning the next.
The Marketing Newsletter came out of a different instinct: I wanted to prove the same approach would work outside of the AI hype cycle, in a category that's older, more crowded, and less forgiving of hand-waving. Marketing as a topic doesn't have the built-in urgency that AI had in 2025 and 2026, nobody is refreshing their inbox afraid they'll miss the next model release. I had to earn attention the slower way, issue by issue, in a space full of newsletters that had a head start on me. It passed 20,000 subscribers running on its own domain, which was a deliberate choice I made for reasons I'll walk through in the chapter on picking a platform.
Running both at once taught me something I didn't expect going in: the mechanics transfer almost completely, and the voice doesn't transfer at all. The cadence, the way I structure an issue, the way I think about a subject line, all of that moved cleanly from one newsletter to the other. What didn't move was the tone. AI For Developers can be terse and a little clinical because the audience wants the information fast. The Marketing Newsletter needs more warmth and more story, because marketers are reading for perspective as much as for facts. I had to relearn my own voice for the second newsletter instead of copying the first one over, and that distinction, mechanics versus voice, shows up again and again in this book.
Two newsletters, two different niches, two different technical setups, and the same underlying checklist behind both of them. That checklist is what follows.