How I Built Product with Attitude from 0 to Bestseller, without Pretending I Have a Viral Playbook
The product framework behind Product with Attitude: person, promise, feedback loops, retention design, and free-to-paid conversion. Part 1 of the series.
TL;DR A newsletter is a product in development. Products have a person, a promise, a feedback loop, a roadmap, and a retention curve. This is part 1 of how I built Product with Attitude from 0 to Bestseller in 6 months.
I’m going to share a few numbers, not to polish my ego, but to explain the shape of the story:
I started this newsletter 15 months ago, from zero.
For the first few months, I didn’t tell anyone in my professional circle that I was running it.
Six months later, it became a Substack Bestseller.
My first article has been read only 322 times in those 15 months and has brought in 5 subscribers since 2025.
My most popular article has been read 106K times in the last 3 months.
I’m now somewhere around 18K readers.
My open rate is 39–42% on average.
My retention rate is, according to Substack, excellent
I’m not a growth specialist. I don’t have everything figured out. I don’t have a viral playbook. I’m not going to tell you to post seven Notes a day. Mainly because most of the time I’d be failing at this advice myself.
What I have is a different bias.
I build products for a living. So from day one, I’ve treated this publication like a product in development.
That means I treat it as something that evolves and needs testing and feedback loops to deliver value.
This article is the first in a series where I break down the product mindset behind PwA: what I ship, what I kill, what I measure, what I automate and what I ignore.
Today: the foundations.
Hey, I’m Karo Zieminski 🤗
AI Product Manager and builder.
I write Product with Attitude, an AI newsletter for 18K+ subscribers developing critical AI literacy the only way it sticks: through practice.
We don’t just use AI. We build workflows, automations, and products with it, while studying how AI itself is built, positioned, and woven into our work.
If you’re new here, welcome! Here’s what you might have missed:
What a Product Is
Many people define a product as something you build and sell.
That definition misses the point.
A product is a repeatable experience of value someone chooses to return to.
Experience
Experience is what happens to the person using the product.
Experience is not just the interface. It includes:
the moment someone discovers it
what they expect before using it
how easy it is to understand
what happens while they use it
how they feel during and after
whether it solves the problem without creating new friction
whether they trust it enough to use again
Value
Value is the reason the experience matters and what the user would miss if it disappeared.
It can be practical:
saves time
saves money
reduces effort
helps someone decide
helps someone finish something
makes a task less annoying
It can also be emotional:
makes someone feel capable
gives clarity
creates confidence
reduces anxiety
makes someone feel seen
gives them status, belonging, or momentum
What Is Publication as Product? A Newsletter Operating System.
Publication as Product means designing your newsletter as a repeatable experience of value built around a clear promise readers trust enough to return to.
What Counts as Value in a Newsletter?
You’re welcome to read my interpretation below, but you can also ask yourself: what newsletters do you come back to, and why?
In a newsletter, value shows up in at least six flavors:
Practical: I can use this tomorrow.
Intellectual: I understand this differently now.
Emotional: I feel seen.
Social: Sharing this says something about me.
Community: I feel part of something.
Identity: This is the person I’m becoming.
If our post doesn’t deliver at least one, it’s not a product. It’s a journal entry.
Product Positioning
What is Your Promise?
Your promise is what readers believe they’ll get if they keep showing up. It’s the sentence they would use to defend their subscription if a friend asked why they pay to read you.
It takes a while to arrive at the promise that sticks, so don’t worry if you don’t have it figured out yet. I didn’t either. I can recommend a writer who helped me figure out mine: Yana G.Y.
My promise, written out:
If you read PwA, you’ll understand AI more critically without losing your judgment, build with more confidence, and do it alongside people you trust, who care about the same things.
Did you notice what’s not in there? No frequency, no format, no topic list. The promise lives above the practicalities.
Why a Promise Matters
A promise gives you a filter. It does not make every decision easy, but it makes it easier. It tells you when an opportunity is aligned and when it’s just tempting. When the promise is fuzzy, every decision becomes a debate.
Examples from my publication:
Should I write about a new model release?
Yes, if it supports critical AI literacy.
No, if it’s just there to hype another model.
Should I run an interview series?
Yes, if it brings like-minded people into the room.
No, if someone just wants to pay me for it.
Should I monetize?
Only if the paid version still serves the promise.
Should I accept sponsorships?
Yes, if the sponsor fits the promise, and offers something useful to the people I serve.
No, if the money asks me to borrow trust from my readers.
Who is Your Person?
Product people call this the ICP, Ideal Customer Profile.
I don’t love the term.
ICPs are useful, but they’re also corporate and flatten a human into a job title and a market segment. They tell you what someone does for a living. They rarely tell you what keeps them reading past their bedtime.
So I think in terms of my person instead. Mindset > demographics.
My Person
My person is curious about AI in the way many thoughtful people are right now:
excited by what’s possible, but not blindly
concerned by its long-term impact on…everything
determined not to sleepwalk through the transition
tired of repurposed hype
has enough experience to spot bad advice and enough humility to keep learning
wants to learn from peers and builders, not gurus
refuses to contribute to slop
That’s my center of gravity.
When I draft a post, I ask: would this help my person?
Write for your person. Everyone else is bonus.
Reader Feedback Loop
A product improves through feedback. A newsletter does too. But not all signals deserve the same weight.
Likes, restacks, comments, shares, paid upgrades. Many writers treat them as a single column called “feedback.”
I don’t.
I like to separate them into different kinds of signals.
Some are loud, public, and very good at stroking my ego, but they don’t always teach me much about the publication.
Others are quieter, less visible, and far more valuable because they show me whether the promise is actually working.
How to Read Newsletter Feedback
Before I treat something as feedback, I ask two questions:
1. How visible is the signal?
Public signals on Substack: Likes, comments, restacks, shares, recommendations, upgrades, unsubscribes
Hidden signals: Survey answers, DMs, repeated phrases readers quote back to you, posts people mention weeks later
2. What might have motivated it?
A like on Substack may mean I agree, but it may also mean I’m showing you I read your article and hoping you’ll read mine. Both are fine. Both are part of Substack culture. But they don’t mean the same thing.
A comment may mean:
This made me think.
I agree or disagree.
I like you, the writer, and I want to show you my support.
I go through my feed and comment on as many articles as possible to boost my own visibility.
Or it might just be someone being kind.
A restack may mean:
This represents me. If I reshare it, I’ll share how I think about this.
My own readers will enjoy this or want to know about it.
I like this author and want to support them.
A share may mean:
This represents me. If I send it to a colleague, they’ll know how I think about this.
I know someone who will enjoy this or want to know about it.
A paid upgrade may mean:
I trust this writer enough to support them.
I want to know what’s below the paywall.
Which one do you consider the strongest signal?
It might surprise you, but for me, the absolute strongest signal is