I love coffee. And the second best thing to a coffee alone on my balcony at sunrise is one with a friend at the local cafe about 300ft away from me. Under it’s droopy tree if the weather permits.

Recently, said coffee was with my mate Bill Kerr.

If the name rings a bell it’s because you might know him from the Open Source CEO newsletter. Bill has over 400K founders and CEOs reading his deep dives. That’s massive, and by size, it makes him one of the most widely read folks in our corner of the internet.

Anyway, the weather did not permit when we met a few months ago. We spoke about living abroad, mental health, my app, his business, and obviously newsletters.

On the topic, Bill told me what he’s making from his.

Well over $50k a month.

And it’s not even his job…

He also said it stopped being a newsletter a while ago. beehiiv has helped turn Open Source CEO into a pipeline-generating media machine. It makes him real money and it hands his sales team at his actual company hot inbound leads. Plus as a cherry on top it’s become a source of growth for everything else he does in his orbit as a founder. Raising money. Hiring. Finding customers for the next thing he does one day. You get it.

Again, his day job is not writing. Not even close. He’s the founder/CEO of Athyna, which places global tech talent and does over $10M ARR.

Every acquisition channel you run now is a cost center. It’s all pay to play. Ads cost you. Sales cost, everything does. The whole growth model is mostly just about how much you’re willing to burn per person and somebody’s job inside a Sheet is to make that number smaller so your forecasts look good. A rough game.

There’s really only one channel where the math flips. Where the thing that finds your customers can also cut you a cheque. Possibly even enough where you’re cash positive per customer acquired.

Negative CAC. That’s what Bill calls it, and he’s not the only one running this two-for-one play. He’s just one of the best executors of the move.

Because, a newsletter with YOUR face on it, written for the exact people you want to sell to, is the only growth channel that can pay you in multiple ways while it works.

You know what would have been nice? Notes and quotes from my chat with Bill. He shared a ton of ideas on growth and “how he does its” for newsletters. On my (short) walk home I wrote what I remembered in my Notes app. Because being on my phone to jot stuff down while sitting with him is lame. Well…

Granola just put their AI notepad on the Apple Watch. Genius. One tap on the wrist catches the walking 1:1, the water-cooler chat, the coffee catchup that becomes a knowledge share. A nice bright green UI so everyone knows it’s recording. Tap when it’s needed. No new device. The best notes you’ll get.

🥷 Start a founder-fronted newsletter for the exact audience you’re selling to, then run ads in it. Theirs AND yours. You get two channels for the price of none: a profit centre that funds itself + a reach centre that fills your pipeline.

When you look at what happens when most founders think about newsletters, you see a company blog nobody reads, written by nobody in particular, and typically optimised for a search engine that has stopped sending clicks.

That’s not this idea.

This play is about you, with your name and face on it, where you are the one writing for the people you want as customers. Where it’s not about your product, but their world and what helps them do well in it.

Nobody forms a relationship with someone reading a company blog. My wife is a content marketer for an AI company and says the same thing. Your newsletter though, that’s different. Maybe it get’s opened on a Tuesday morning at 9am by a VP who’s been reading you for eighteen months and now thinks of you as the person who understands their problem.

Ok. Simple enough so far, so where does negative CAC come in?

First, even with a small niche base, you start to sell ads in it. That’s the start of the profit centre. Just one email from Bill typically has $10k to $15k of ad inventory, sold to advertisers who are not Athyna. And sometimes these advertisers paying to reach the Bill’s audience become warm leads and customers themselves for Athyna. AKA the growth of the newsletter machine that warms up Athyna’s future customers is being funded by Athyna’s future customers.

Then in the mix of other ads, you run your own ads in it. That’s the reach centre. Good Times, Little Moments, my free builder tools, bits. See, I just used my own channel to drive awareness of my own products, and Granola and Tendem technically paid me to do it today.

Owning a newsletter channel is the single best source of free, permanent ad inventory you will ever have for your own stuff.

Your CAC on that channel is negative.

Let’s break it down, but first a very quick word from the folks helping pay for today’s email.

To execute today’s idea well, you need to know what your people already read, what those newsletters charge, and who’s advertising in them. This is a AI←→Human task Tendem can help with.

Tendem drops a vetted human expert straight into your AI chat over MCP. You mention it mid-chat and it will scope and quote the task for you right there. Then the magic → a real person sends you the finished job back into the same chat.

For this move, ask Tendem to “find every newsletter read by [your ICP], with subscriber counts, rates, and current advertisers.” You’ll get a usable precise list probably in just a few hours. Tendem is built by Toloka who’ve spent a decade doing human-in-the-loop work for the frontier labs. It’s very very good.

Free distribution is gone guys. Less than a third of Google searches send a click anywhere now thanks to AI Overviews. The top of funnel has been pinched on us.

But also since we’re playing the AI blame game, AI has killed personality anywhere and everywhere. Yes it’s all very good, but for content it’s made everything sound the same. If you let AI do the work (and MANY companies do) people know slop when its slop even if they don’t know—you know?

So, when anyone can generate anything that resembled competent content that floods all the platforms we used to use for acquisition, that competent content is worth nothing. Ads made by AI. Infographics signed by Claude. Posts people are comfortable posting as theirs written by Chat. People care about a specific and real human with a name and face and personality.

You are and can be that person for someone.

The trust you will build with flaws, your face, candor, and of course being useful is the channel. When Bill’s readers need to hire someone, they think “Oh, that Bill guy seems legit”. They then just reply to an email. Pipline!

And on the topic of platforms, when you build your own channel like this, you’re not caught in the algorithm rat race where the rules change whenever and however they want or you can lose everything if the platform so decides.

With newsletters, it’s your game, your rules, and your players. And if you want to own the stadium too, build yours where I build mine, on beehiiv.

Bill calls the self-fuelled machine he runs the media pyramid. And like all good pyramid analogies (and the best cakes btw), it has 4 layers.

→ Founder brand. The foundation to start from. This is his LinkedIn plus this newsletter. He treats it as top and middle of funnel. The top part is what pulls people into his orbit, and the middle because it’s where the trust lives which is an accelerator for when anyone might be primed to do some hiring through Athyna.

→ Owned media. Beyond his main newsletter, Bill and Athyna actually have 3 other daily tech news brands which expand his reach surface. By design he deliberately runs these in stealth with no Athyna branding on them because of how much ad space he uses for Athyna and Open Source CEO. His ecosystem is like a garden watering itself.

→ Creator partners. This is a specific layer doing what Bill dubs “the heavy heaving”. It’s not part of today’s move but I mention it because a) it’s in the pyramid so I have to, and b) because it’s a growth motion that’s easier once you have a newsletter. More on this in a second.

→ Newsletter ads. Using the cash generated from L1 (his founder brand) and L2( his owned media), Bill sends capital towards being an aggressive buyer in the newsletter ad space until Athyna is simply everywhere in it.

This is the media machine. Build or buy good media, run external ads, run internal ads, rinse, repeat. Twelve months into this move and Athyna’s web traffic was up 2,000%.

The first time Bill and I did work together was when he sent me a PandaDoc for a SAFE to invest. Except I didn’t send him any money.

Athyna put their marketing budget on the cap table, raising a $2.5M round filled by newsletter operators. Bay Area Times, Strategy Breakdowns, me, and others. 12+ creators with audiences ranging from 10k to half a million who all now holding a vested interest in the company reaching more people.

The buy-in was commitment through my attention, my channel, and my willingness to fold Athyna into my own founder media layer. Equity for reach through trust.

Newsletters are profit centers with a four main cash columns:

→ The ad network. Just a simple marketplace that just matches ads to you, one click to insert, get paid. Simple. Not great for big bucks but it can get you off the ground from launch day. It’s a way to monetize before you have the leverage to negotiate your own direct deals.

→ Direct sponsorships. Much higher rates, bigger deals and clients, but more work. This is where you run a real sponsorship business (this is the column I picked) and do reports and get on client calls. And you don’t actually need a big audience for this, just the right audience.

→ Paid Recommendations. A growth feature on beehiiv that helps you grow and/or allows you to get paid to help others grow via referrals. Like a CPC ad network for newsletters creators to promote their newsletters to each other.

→ Paid subscriptions. Not necessarily a decision of ads or paid, some creators do both. I personally think its a better business to keep the newsletter free with no gate on value. It also means people expect and are ok with ads, which is an easier B2B business to manage that a B2C business. But depends on your niche. A very small niche for something like finance can command a high monthly sub price. Lenny makes millions a year this way.

And if you pick beehiiv as your platform, whatever you earn on any column, they take nothing.

Now, a quick comparison back to negative CAC.

Assume you’re the founder of a B2B product. Not unusual to see organic CAC at ~$950 and paid CAC around $2k. But, if you chose to spend money acquiring people to your newsletter instead of your product…a subscriber would cost you somewhere between $0 and $10.

Yes for $2 they’re not acquired as a customer, but they’re acquired as a lead who is now reading you and building a relationship with you over time. If you are good at building trust by being credible and making good content, they might come to you as a very warm lead.

Here’s some made up numbers for a weekly newsletter with 3,000 subscribers in a tight B2B niche to napkin out the math.

Before a single reader turns into a customer of your actual product, your channel is $900 up and has handed you $600 of free inventory to market your own product. If you use that $900 to get new subscribers, you’d probably grow by about 400 relevant readers/prospects.

“But I don’t have an audience…”

That’s fine. You don’t need a big one I promise.

An 4,000-subscriber B2B newsletter in a very specific niche can ask for around $1k per placement ($250 CPM). A 50k-subscriber lifestyle list might struggle to get that $1k ($20 CPM). 6X less readers with 2X+ the money.

Advertisers can get eyeballs for cheaper elsewhere. If they work with you its because they want access to a specific group you have an in with.

My friend Seth just started a newsletter and he’s designed it around exactly this. Small list, hyper-targeted. His goal isn’t CPMs in the traditional sense. He wants brands to sponsor events he runs with their ICP over an intimate dinner he hosts. The list is the guest list and the guest list is the paid product he wants to sell to B2B brands with expensive enterprise licenses.

“Fine I get the audience size thing. Still, I don’t have enough time”.

Bill spends literally a few hours a week on Open Source CEO. Otherwise he’s being CEO.

Tyler Denk is the Commander and Chief of beehiiv, a $33M ARR company, and he also pockets $500K+ a year from Big Desk Energy with only 5 hours a week.

And me…I have a full-time job. I spend about 10 hours a week on The Diff and average about $15K a month My best month ever was $42K, but that’s not the norm although I’m trying to make it so—s/o to beehiiv who’s helping me do it.

The point is you can build a newsletter business while your business stays the priority. And the more you reinvest back into it, the faster the profit centre grows.

Even if the money never showed up I’d still tell you to do this.

When you write and your name and face is on it, you build your brand and your credibility and your relationships. You think better. And as a founder, you keep discovering problems people in your space have and what they actually care about which becomes the raw material for everything else you’ll build.

Bill quotes Scott Galloway, and thinks that within five to ten years, how big your audience is will be part of how boards decide who to make CEO.

There’s just no losing version of this.

Building up isn’t the only door. If you want reach faster than you can earn it, you can buy down from someone who already has it.

HubSpot bought The Hustle in 2021 for ~$27M, then Starter Story this Feb, pushing its YouTube network past 2.9M subscribers, bigger than Morning Brew’s.

Robinhood bought MarketSnacks in 2019, scaled it to ~36M subscribers then spun it into a media subsidiary.

Zapier bought Makerpad, the place people go to learn the problem Zapier solves. DigitalOcean bought CSS-Tricks, whose readers literally rent servers.
Semrush bought Backlinko to own the category’s reference material.

Stripe, Pendo and Semrush, all running some version of this move too.

One rule if you had to do this that HubSpot shows well: don’t absorb the brand. The Hustle is still The Hustle. Don’t kill the thing you paid for trying to claim the earned trust as your own.

My own strategic move was migrating to beehiiv in January and I’ve said why before. But for this specific play, four things matter:

→ It defends the profit centre. Monetisation is fully built in for you under one roof. If negative CAC is the point, don’t run it somewhere that cuts your margins.

→ You own the whole asset. Real API and an MCP server, full export, your list and your data out whenever you want.

→ You can read the audience like a product. Segments, polls, surveys, click-level data. Very Hormozi. You’re publishing and watching which 300 people clicked the pricing-adjacent thing and treating that as a lead list to send to.

→ It’s being built for AI discovery. AI Crawl Controls with Cloudflare shipped in June so you control which bots read your archive, plus work on getting your content cited in AI answers. This is the ballgame now.

And it’s free for your first 2,500 subscribers, so the experiment costs you nothing. If you want the full creator stack I use, grab my code THEDIFF30 for 30% off your first three months.

We’ve covered Bill and Tyler and HubSpot, so here are just two other examples done differently.

PostHog has build mode with 75,000+ subscribers. It’s about helping engineers and builders get better at building products. How to talk to users, how to find product-market fit, how to hire. Not about PostHog.

They don’t sell ads in it so this isn’t the negative CAC idea, but it’s a pure reach centre and example of a company “blog” that isn’t about the company. They do run house ads about PostHog though in it, and a single build mode send drives more clicks to their site than the average $5K newsletter sponsorship they run. Their content marketer describes every edition as the equivalent of going viral on Hacker News, except consistent, and on a channel they can reach whenever they want.

Takeaway: owned beats rented by an order of magnitude, and the fastest way to get a newsletter people actually read is to stop writing about yourself.

Greg runs Late Checkout, a holding co. of internet businesses. He also writes Greg’s Letter to around 160k people next to a 700k YouTube channel.

His sequencing is every business in his portfolio he always starts as an audience or a community, and then builds the product into it. Greg gathers the people and lets them tell him what the thing should be. He does very well.

Takeaway: the audience doesn’t have to be marketing for the company. It can be the raw material you build the company out of.

I’ve been making Shorts for about 2 weeks now. I’m going to start with some longer form as well in the next couple of weeks. I’m still figuring it out but the general angle is “60 seconds, 1 idea”. We’re having fun over there.

Every other channel you run gets more expensive each quarter and will die the moment you remove your credit card. Build one that gets cheaper, compounds, and can even be used in return for equity. Shoutout to Seth who started his faced newsletter last week—love it 👇

So, what could you write about?

p.s. If you start one or have one, email me with the link. I’ll read it and if relevant to to everyone here, will feature it.

› The macro: why the free top-of-funnel closed with data. → In 2026, less than one third of Google searches still send a click (6 min)

› The case study: beehiiv’s breakdown of Bill’s numbers and the ad-network origin story. → The founder who turned his 400k+ newsletter into a negative CAC machine (9 min)

› The framework: Bill’s own write-up of the four-layer pyramid. → The Negative CAC Media Pyramid (11 min)

🔨 A tool → Food_For_Claude. You are what you eat. The same is true for your agents. Food_For_Claude helps “make your claude smart AF”, it’s a cherry picked list of MCPs and Agent Skills that make working with Claude way better.

📺 A listen → Tyler Denk breaking down his exact newsletter growth playbook.