What is negative CAC for a newsletter?

Negative CAC means your cost to acquire customers flips: you get paid to acquire them. I didn't coin the term. I think I first heard it from another newsletter operator, and the idea clicked for me at a newsletter conference in Austin.

"That's the negative CAC model. Your cost to acquire customers is you get paid to acquire customers. I wouldn't promise it, it depends on a lot of facts, but even if it was 50%, instead of paying a dollar you're paying 50 cents."

Where did the idea come from?

At that conference, a B2B newsletter for women executives presented their whole model. Every new subscriber got a welcome email every day for about seven days. Each one gave real value first, but inside the content were software deals, like Notion or Airtable, that paid them a kickback when a reader signed up.

As I remember their numbers, they paid around 75 cents to get a subscriber and made 85 cents to a dollar from that person in the first seven days. That's why they could keep pouring money into growth. I've since heard of one B2B newsletter making about $6 per subscriber in the first five minutes through an offer page.

How does the math work for a local newsletter?

I usually pay 30 cents to a dollar per local subscriber on Meta, mostly 30 to 70 cents depending on the size of the town. The question is how many new subscribers need to take a paid offer to cover that.

Divide what a subscriber costs by what one lead pays you. That tells you the take rate you need to break even.

Cost per subscriber	Paid per lead or sale	Takers needed to break even
50 cents	$20	1 in 40
50 cents	$30	1 in 60
50 cents	$50	1 in 100
$1	$25	1 in 25 (4%)

These are round numbers to make the point, not results. Meta costs also climb as you scale spend, so the math never holds perfectly.

Has anyone actually done it?

Yes, one operator I know. He spends about $25 to $30 a day on plain subscribe ads. He made a deal with a real estate agent who pays him $30 every time a new subscriber says they want to buy or sell a home and shares their info. He gets about one of those a day.

His ad spend is covered, so his list grows for free. He took my idea and had it running in about a day, and it looked crappy. It still worked. If that holds consistently, it changes everything about my own model. That's his result, not mine.

Where does the money come from?

• A lead question for a local business. Ask if they plan to buy a home in the next 12 months, then whether they want a realtor to reach out. The realtor pays per yes.
• A strong first-visit offer. A business with a high lifetime value, like a med spa, could give away a free first treatment and pay you per taker. Pest control could do one free visit. It has to be a real deal. If it's 10% off, nobody's going to care.
• An offer to business owners. About 15% of local subscribers own a business. Show them something like "first ad 50% off this month," a $100 or $200 purchase. If about 1% of all subscribers take it, you can cover your list growth. Even a media kit shown to people who say they own a business can pay for the flow if 2% buy a $300 ad.
• Your own product. A paid tier, a $29 prompt pack or a $50 product. At 50 cents a subscriber, one buyer per 100 new subscribers breaks even.
• Paid recommendations or affiliate offers. These work better for national and B2B newsletters than for local.

Why doesn't SparkLoop solve this for local?

Paid recommendations only pay when the new reader actually engages with the other newsletter. In local, a lot of people sign up and never open, so you don't get credit. My rough example: a $2 average payout where only 25% engage works out to about 50 cents per subscriber. I tried it, and for my cheap local lists it wasn't worth the work. That's also why local is harder than B2B overall: a B2B audience buys software, and a local consumer audience mostly doesn't.

Louis Nicholls of SparkLoop told me on my podcast that local newsletters typically earn about 50 to 80 cents per new subscriber from recommendations and offers combined, and that a good payback period was around six months when he started in 2018 and has shrunk to near zero. Those are his numbers.

What changes if it works?

Everything about your budget. Most small publishers spend $20 a day or less on Facebook ads because that's all they can afford. Fifty cents to a dollar per subscriber is cheap one at a time, but at scale it's a lot of money to wait months to earn back through advertisers.

"Imagine if the growth cost was zero, right? I would double, double the spend, triple the spend."

The question stops being what a subscriber costs. It becomes what the first five minutes after subscribe produces. It also means you don't wait until you have 10,000 or 30,000 subscribers to figure out money. You monetize from the first signup.

What if you only get partway?

Still worth it. If offers cut your acquisition cost by 30%, 50% or 80%, that money goes back into ads. Getting a 50-cent subscriber down to 15 cents is a 70% cut. A realistic first goal for a new local newsletter spending around 50 cents a subscriber is getting to neutral.

Why is it hard?

• You need local businesses willing to pay per lead or pay for a slot. This is the real bottleneck.
• You have to sell those businesses, which is real work, and every market is different.
• You need tracking so every lead is counted before the business gets it.
• The welcome flow can't feel like constant pitching.

I'm honest about where I am. I built greetform to help publishers make money back on new subscribers, and for a while I couldn't even use it fully on my own brands because I didn't have enough partner businesses lined up to advertise. It's something I'm working on, not a result I can show you yet.