The Founder Who Turned His 400k+ Newsletter Into a Negative CAC Machine

At a Glance

Newsletter: Open Source CEO

Founder: Bill Kerr, CEO of Athyna

Subscribers: 400,000+

Trailing 12-month revenue: ~$375,000

Projected 2026 revenue: $1M–$1.5M

Pipeline contribution: Up to 17% of Athyna's pipeline

Platform: beehiiv

Most founders treat a newsletter as a vanity channel. Bill Kerr built a newsletter that gets paid to find customers.

Bill is the founder and CEO of Athyna, a company focused on finding nearshore technical and post-training talent for big tech. He started Open Source CEO, a newsletter about founders, strategy, and the honest mechanics of building companies, on beehiiv. It now reaches more than 400k+ subscribers, generates close to $375,000 in annual revenue, and has driven inbound conversations with six of the ten largest venture funds in the world, and at the same time it's running ads, it's filling Athyna's sales pipeline.

It's a framework Bill calls negative CAC, and it's one of the most quietly powerful growth models in B2B today.

The Origin: A Channel With No Friction

Before Open Source CEO, Bill hosted a podcast. It grew to 25,000 downloads a month from a standing start, which, by any measure, was a real result. But it drained him.

He started thinking about what a founder channel actually requires to be sustainable. Something He’d still be doing in five years. His framework: find the channel with the least amount of friction.

For Bill, that was writing. He'd always been good at it. He liked it. He started Open Source CEO as a series of founder interviews, the lowest-lift format and a natural excuse to build relationships with people he admired. 

Over time, he graduated to deep dives on companies, strategy breakdowns, and a built-in-public format that pulled back the curtain on how Athyna actually operated.

The original goal wasn't revenue. It wasn't even building a pipeline. It was allies.

"I wanted potential investors, people that might become clients, employer brand, people that might refer," he says. "At the end of the day, it was really about building a base of allies."

That goal hasn't changed. The mechanics around it have gotten significantly more interesting.

The Negative CAC Model

Here's the basic premise: most companies are fighting a battle on Meta and Google to acquire customers. They spend $1 to get back $0.90. Every customer costs something.

Bill flipped it.

When Open Source CEO sends a newsletter, it typically contains $10,000 to $15,000 worth of ad placements, sold to external advertisers. Those sponsors pay to reach a highly engaged, founder-skewing audience. The newsletter makes money on every send.

But embedded in that same send, whether through an Athyna ad slot or through the brand association Bill has built over years of writing, leads enter Athyna's pipeline. Readers who've been following Bill for months already trust him. When they eventually need what Athyna offers, they directly reach out.

"We've just acquired a client with a lifetime value of $80,000 for positive $15,000," Bill explains, "because we've sold $15,000 worth of ads."

That's negative CAC. 

It's a small portion of Athyna's overall pipeline, but it's growing. And Athyna has since extended the model, building additional newsletter assets in stealth, audiences of 200,000 or more, unbranded as Athyna properties, that operate on the same negative CAC funnel.

"While all of our competitors are fighting the battle on Meta and Google to try and win a few clients, we're actually getting paid to acquire clients," he says. "It's the most unique, unfair advantage in the world."

What beehiiv Made Possible for Open Source CEO

When Bill first decided to start a newsletter, he asked his network for a recommendation. Out of ten responses, five said beehiiv. The platform was less than a year old at the time.

He signed up. Within six months, he'd acquired two other newsletters, one on Kit and one on Substack, and moved them over to beehiiv. The comparison wasn't flattering to the competition.

"Substack has absolutely nothing that you need as a newsletter operator," he says. "It has zero features that you actually need."

What he found on beehiiv was a platform moving at a different pace entirely. Bill now shares beehiiv's product velocity with Athyna's own product team as a benchmark for how fast a company can ship and communicate new features.

The specific beehiiv capabilities that have mattered most for Open Source CEO:

Analytics. Bill calls beehiiv's analytics suite the deepest of any ESP, by a wide margin. The single metric he tracks most closely is verified unique clicks, a bot-free click metric that beehiiv is, as of this writing, the only platform to offer.

That metric actually started as a conversation. Bill and Tom from Strategy Breakdowns noticed their click-through rates dropping. They brought it to Tyler Denk, beehiiv's CEO, via Slack. What followed was hours of back-and-forth, diagnosis, and a product launch within weeks.

"Not all founders do that," Bill says. "It's very rare."

Automations. Open Source CEO's automation stack is now sophisticated enough that a reader who clicks on a partner's content gets routed into one automation, while a click on a different partner's content sends them down a different path entirely. Personalized content blocks shift based on segment. The engine runs without Bill touching it.

The Ad Network. For early-stage newsletters without direct advertiser relationships, beehiiv's ad network gives publishers a path to revenue from day one. Bill credits it with getting Open Source CEO off the ground before the newsletter had the leverage to negotiate its own deals.

Recommendations and referrals. "Some of our highest quality subscribers have actually come from beehiiv's tools," Bill says. "I know that's the same for a lot of my friends."

From Hobby to $1M: How the Revenue Actually Works

Open Source CEO generated approximately $375,000 in revenue over the trailing 12 months. It was built as a hobby, run by Bill in his spare time away from Athyna and a single contractor working 20 hours a week.

In the last quarter alone, revenue reached $170,000. At that run rate, without accounting for growth, the newsletter would hit $700,000 annually. With conservative growth factored in, Bill projects $1M to $1.5M in 2026.

The monetization model has two components.

• Ad placements. Rather than selling a single main placement, Open Source CEO runs two ad slots per newsletter and charges for each as if it were a standalone placement. Advertisers don't push back. They sell out.
• Content partnerships. For companies that want Open Source CEO to write a deep-dive piece, the 0-to-1 origin stories Bill has built a reputation for, the rate is $12,000 to $15,000 per piece. Two years ago, roughly 1 in 20 pieces was a paid placement. A year ago, it was 1 in 8. Today, the ratio is closer to 1 in 3.

Companies now come inbound to request them. Deel was the first major content partner. Bill.com reached out asking for a feature. Figure Markets, a blockchain technology company, had its PR team contact Bill ahead of the company's IPO to roll out the announcement alongside an Open Source CEO deep dive.

"Our zero-to-one pieces are becoming like a stamp of approval in the tech community," Bill says.

Beyond the Pipeline 

The second-order effects of a newsletter at this scale are harder to quantify but possibly more valuable.

Up to 17% of Athyna's pipeline can be attributed to Bill's ecosystem, which includes his newsletter, social media, and network bundled together as a single attribution channel. But the list of effects that don't show up cleanly in attribution is long.

Some of Athyna's best hires arrived because they already read Open Source CEO and wanted to work there. Inbound investor inquiries have come from Sequoia, TCV, GGV, and Insight Partners, roughly six of the ten largest funds in the world, largely attributable to the newsletter.

"There's a pipeline, definitely," Bill says, "but then there's a million other metrics that it also positively affects."

The Framework, Distilled

Bill doesn't frame this as advice for people who want to start a newsletter. He frames it as advice for founders who want to build something sustainable.

Find the channel with the least friction. 

Once you find it, the payoff isn't reach. It's that the funnel flips. Normally, sales and marketing is getting people to know, like and trust you. With a newsletter built over years, readers arrive already trusting you. The bottom of the funnel becomes the top.

That's the real return on founder media. Not the ad revenue. Not even the pipeline. The fact that by the time someone needs what you offer, you've already done the hardest part.

Start Using beehiiv

Open Source CEO is proof that a newsletter can be a legitimate business unit, generating standalone revenue, driving pipeline, and building the kind of trust that no ad spend can replicate.

If you're a founder thinking about what a newsletter could do for your company, beehiiv gives you the analytics to understand your audience, the automations to act on what you learn, and the ad network to monetize while you grow.

Start for free at beehiiv.com