He went from tinkering around on the internet, sharing his random business ideas, to writing a newsletter that makes him half a million per year.
In just 4 years, he’s grown his newsletter to over 59,000 readers.
And he makes about $500,000 a year from that newsletter.
And did I mention this is his side hustle? 🤯
CJ Gustafson is the creator of the Mostly Metrics newsletter. He’s a full-time CFO so he writes about the topics he’s tackling in his day job. You know, fun stuff like CAC, LTV, and balance sheets.
Did your eyes glaze over as hard as mine did?
But CJ keeps it fun, infusing these boring topics with some of the worst Dad jokes I’ve heard. But he definitely makes you laugh.
And that’s one of the reasons I think he’s grown so fast.
Mostly Metrics is now a Top 15 Substack Paid Newsletter in the Business category. And if all that wasn’t enough as a side hustle, he also hosts the Run the Numbers podcast where he interviews CFOs.
The Growth Timeline of Mostly Metrics
Let’s take a look at the growth timeline to see how consistent this growth has been. I’ve charted out his newsletter subscriber counts, as well as social media accounts.
That’s a beautifully sustainable growth chart if I’ve ever seen one.
The thing that stands out to me most is that he’s built this massive business without that big of a social following.
Okay, 36k followers (combined from LinkedIn and Twitter) is nothing to sneeze at.
But it’s nothing compared to some of the bigger creators you see out there with 100k+ (that can only grow their email list to 5k subscribers).
Well done, CJ.
Let’s take a look at how CJ is making money from the newsletter and podcast.
How He Makes Money
Remember, he has a full-time CFO job which I don’t have insight to but from a super-sophisticated Google search, I’d guess $150k-$200k:
But I’m not including that this in the $500k estimate. So here’s how that breaks down.
Paid Newsletter
While you can subscribe for free, Mostly Metrics also has a paid version of the newsletter.
He charges $150/year or $15/month to become a subscriber where you get more in-depth articles.
But checkout the “benefits” of the annual plan.
That 3rd line reads: “Support a writer sharing 30,000 hours of on-the-job insights.”
I haven’t seen many creators do that, and it is a nice last ditch effort to remind people that there’s a real person behind the screen.
At 59,000 subscribers, with a 4% conversion rate to paid (what I’ve seen in the past), I’d guess he’s at about 2,360 paid subscribers.
And the bottom of one of his posts shows a paid subscriber count of “Thousands”, which makes me feel more comfortable with that number.
So at $150 per year, with 2,360 subscribers, that’s $354,000 per year.
Not bad for one piece of the monetization pie 🙂 Okay, let’s dive into some others.
Sponsorships & Brand Partnerships
Moving on to the sponsorships side of things.
Sadly, I couldn’t find a sponsor page that shows rates he’s charging. But, he has talked about pieces of this before.
Podcast Sponsorships
CJ sells his podcast sponsorships 3 months at a time and often packages them up with newsletter spots. Which makes sense, as people need to be pummeled with a brands name before actually looking into them.
Especially CFOs of tech startups. These things just take time.
Also, he’s working with the Turpentine Network to produce his podcast, so they might handle some of the podcast sponsorships.
Guest Posts
Okay, this is where I’m super interested. CJ gets sponsors for his newsletter like a typical operator would, but often he also packages those up with guest posts.
As in, the sponsors get extra content they can publish on their own site. CJ gets a backlink, more distribution, and gets paid for it.
Don’t worry, I dig into this more in a bit, as it’s 100% a growth lever.
But he did say that he now charges a minimum of $5k-$10k per post.
Sponsorship Packages
CJ will package his newsletter sponsorships with other things like:
- Live webinars with the companies customers
- Podcast ad reads
- Newsletter posts
He gave a $100k example for a 3 month package that included the above. And I have a feeling he’s done at least one of those before.
In 2024, CJ published 160(!) pieces of content to his newsletter. That’s like one every 2.6 days.
With over 50k subscribers, and a highly targeted/influential B2B audience, I’d say my estimate of $150k from sponsorships might be on the low end.
Especially since in April 2024, when he had around 44k susbcribers, he said that paid subscribers were only 20% of the monetization pie.
Maybe one day CJ will give us the full picture 🙂
The Growth Levers of Mostly Metrics
Alright, let’s jump into the growth side of things.
Here are some of the growth levers I found from CJ’s journey.
🍨 1. Dad Jokes and Ice Cream. Who said finance topics have to be boring? 59k finance professionals think otherwise and love how CJ brings some flavor into the content.
💬 2. Own a Common Phrase. This tactic is exactly what got him his first 1,000 subscribers.
🧩 3. Build the Puzzle. Taking a page out of one of the biggest paid newsletters out there, this is how CJ will never run out of content ideas.
🥞 4. The Triple Stack Approach. This might be my favorite method because it combines growth, content creation, and monetization in one.
🔄 5. Recommendations Swaps. How can you partner with bigger creators in the space? This is how CJ was able to kickstart the recommendations flywheel.
There might be a bonus one at the end. But let’s get into it!
Stumbling Into Metrics
You might not consider this a typical growth lever, but if he didn’t listen to the data, you wouldn’t be reading about CJ today, so I wanted to include it.
CJ didn’t just one day start his newsletter, Mostly Metrics, and it happened to work out.
He actually started with another newsletter called “Steal My Idea” where he would break down some cool business ideas he had and then explain how it could work and make money.
He got the idea from Sam Parr and Shaan Puri sharing business ideas on the My First Million podcast.
And this first newsletter wasn’t a traditional one. In fact, it started out as an infographic he would send with almost no text.
If you’re like me and don’t naturally have “Display images” turned on, this email with just an infographic was probably a bit confusing. 🙂
After the image, he had a section in the newsletter called “Potentially reliable stuff I read at 3AM:”
It was just links without context or any reason why someone should click them.
Note: I’m not showing this to make fun of CJ, but just to show you that we all start somewhere. And getting started can help you find your “niche.” Don’t let perfectionism hold you back.
He was sending these infographics and after 4-5 posts realized people might want some written context, so he started sharing more context and answering questions someone might have about his ideas.
He still included these infographic style visuals, but broke them up so he could add some color where needed.
And then on issue 18, he decided he was going to talk more about Business metrics. Not exclusively, but he wanted to talk about them…sometimes. 😆
It makes me way too happy to look back on people’s stories and see exactly where they started pivoting towards their “thing.”
In February 2022, 15 months after starting his newsletter, I think he started realizing people really liked the metrics topics and weren’t so into his ideas. Poor CJ.
He started following the numbers. His posts about metrics and data got 3 likes while his Steal My Ideas posts only got 0-1 likes.
Sure the numbers are small, but when it keeps happening, there might be something to pay attention to.
And of course, these are just the public numbers, he might have been seeing something on the backend that made him realize what was happening.
Finding Mostly Metrics
Over time he started writing only about business stuff, and then realized people wanted to hear his take on only metrics topics.
How did he come up with the name for his newsletter?
One day he was in an Uber and the driver asked him what he did for a living. He offhand mentioned that he was a writer.
The drive then asked, “What do you write about?” And CJ, not knowing exactly how to answer said “Mostly Metrics.”
And thus the brand was born.
The moral of the story here is to listen to your readers and take note of what they’re enjoying and why. If he had just kept writing these Steal My Ideas posts, I’m not sure I’d be writing about his newsletter today.
Okay, time for the first real growth lever.
1. Dad Jokes and Ice Cream 🍨
If you remember my 2024 recap, I mentioned wanting to have more fun with this content. And that’s one of the reasons I chose CJ’s newsletter to cover this week. It’s just…fun.
What do I mean? Well, lets take a lot at a recent post CJ made:
What finance guy, or CFO for that matter, starts his written essays with that? You can’t help but chuckle at how bad of an intro/segue that is.
And dad jokes aside, CJ has fun with his work in other ways.
Walter 🐕
CJ’s dog makes a constant cameo as he hits certain subscriber milestones.
Every 1,000 subscribers that Mostly Metrics gets, CJ takes his dog Walter out to get some ice cream.
Talk about making newsletter growth fun. And it gives him a way for people to feel connected to CJ.
And the best part? It’s a natural way CJ can keep talking about the newsletter without it feeling promotional.
Walter has become such a staple among CJ’s readers that he even created mostlyicecream.com where he shares more pictures of Walter getting his favorite treat.
Lean into your personality and what makes you unique. It builds affinity with your readers and over time they’ll start to get the “inside jokes” and feel like part of a community.
Make it fun, people will remember you.
2. Own a Common Phrase
1,000 subscribers is a great milestone for many creators in the beginning. And CJ tried a few things to get there, but this one worked best for him.
In the early days of Mostly Metrics, CJ decided he wanted to “own” a phrase. Essentially, when anyone mentioned that phrase, he wanted his content or his profile to show up.
And to start, he decided that “CAC” (aka customer acquisition costs) was that phrase.
So he wrote a super comprehensive post about it on his site.
Then took he to Twitter to comment on every post that even mentioned the phrase CAC.
His criteria were that it had at least 20 likes, was posted in the last week, and it made sense for him to post his content below it.
This kind of reminds me of Ben Tossell’s “Reply Guy” strategy.
Here are some more examples of CJ “spamming” his content 🙂
He found one that didn’t explicitly mention it, but the answer to the person’s question had to do with CAC, and he responded with this:
And when Alex Hormozi posted the following tweet, I’m sure CJ was so excited to be able to come in and comment his article there:
His comment even got some likes and bookmarks on this one, so I’d guess he probably got a few subscribers from it.
I said “spamming” above because I know CJ knows I’m kidding, but I want to be clear: I wouldn’t actually consider this spamming.
It’s more of him intentionally finding relevant content to answer a question and post his own article below it. The key? It’s a well-written, valuable article.
He told Simon Owens that he did this every night for about 4 months and that’s how he got his first 1,000 free subscribers.
It’s a lot of work, but you have to hit escape velocity somehow.
Stock Options
Another example of this was with an article he wrote about employee stock options.
He wrote that piece and started doing this commenting strategy. Companies started laying off tons of workers, and that can really impact someones stock options.
So the time was right, and he started commenting on news articles about employees getting laid off. Here’s a great example:
He said these stock options comments ended up getting him hundreds of subscribers because it was such timely content.
This is a great example of finding a strategy that’s working, and doubling down when there’s a newsworthy topic going around.
3. Build the Puzzle 🧩
CJ has mentioned that Lenny Rachitsky is someone he looks up to. And I think anyone running a paid newsletter in the B2B space probably feels similarly.
Lenny thinks of his content and job like a puzzle, trying to fill in the gaps, and help with any challenge his audience might face.
CJ resonated a lot with this. He’s building a database of great content, and since most of his content is Evergreen, meaning people will still find value from it years from now.
That lends itself well to having him continue to show up and get shared around as new people discover his work.
He said people are always asking him if he’s going to run out of content ideas, and he always says no. Even once he’s created all the puzzle pieces, he can still go back and make the edges sharper and refine those posts.
If some pieces become a little outdated, he can either write a new one and make it more relevant to today, or update old articles.
It’s kind of like building an encyclopedia of content for your audience.
Complete Guides
While building his puzzle, CJ has created a number of “series” posts he calls “Complete Guides.”
And when I went back to sort all of his articles by the most popular or “Top” on Substack, the top 5 consisted of purely Complete Guides.
And this makes me feel like CJ and Lenny are onto something with this “build the puzzle” approach.
Of course, not every one of these posts is going to strike a nerve with readers, but when you’re helping to explain a big piece of an industry, people resonate with those and they become evergreen sharing machines.
Monthly Themes
It can be kind of challenging to keep up a cadence of writing multiple times a week. You might be inspired for a few weeks and then fall off.
During the chaos of the year it can be hard to take a step back and think big picture. That’s why CJ plans out his content calendar at the end of the each year for the next year.
He hasn’t always done this, but after he wrote one “series” of posts (i.e. the complete guides), he thought it would be really nice to have a specific theme moving forward.
This helps keep your readers excited for what’s coming, and also creates a feeling of being in the know.
I’d bet his post about this calendar got a few replies with ideas for what to include, or people to interview, etc.
It also makes filling out the puzzle much more strategic and straightforward. 🧩
4. The Triple Stack Approach 🥞
Remember how I mentioned earlier how CJ gets paid to write guest posts? It’s wild, so buckle up.
Creators are often struggling to make it work with sponsorships, especially when they’re just selling straight inventory in their newsletter.
But CJ knows better, and takes an approach Justin Moore would be proud of.
He thinks about his work with brands more like a partnership vs a one-off transaction. CJ works with brands and gets paid to write guest posts for their site.
The first time he got paid for this was a deal he did with Brex. He told Nathan Latka that Brex wanted to pay a lump sum for 6 posts in the beginning.
While he didn’t disclose exact figures, he said it was between $1k and $2k per post, for a pack of 6 articles. So, $6k-$12k for a company to publish your content?
Yes, please!
But it gets even better.
Repurposing Angle
It’s not like he’s writing content he can’t sent to his audience. These posts he’s writing for other places?
They are either reposting something he’s already written (seriously), or he writes something new and gets to repost it to his newsletter as well.
This screenshot was taken from a post published on Brex.com, you know, the company that paid him $6k to $12k for his articles:
That was one he had already written and published on his own site. He didn’t have to create any “net new” content for this deal.
They just republished the whole article, dad jokes and all.
Borrowed Audiences
But wait, it gets even juicier. 🧃
These companies have sometimes hundreds of thousands of his ideal readers in their audience. And they’re sending CJ’s content to them via email.
That’s distribution to an audience he didn’t have to build. And most of the time these are the exact people he wants as readers.
And they’re paying him for it.
Stack It Up
Okay, let’s put some syrup on top and recap:
- They’re distributing his content to their readers. Oftentimes these are perfectly aligned to his content and probably drive a good deal of subscribers.
- The content also lives on their (high domain authority) website for years.
- He gets a nice backlink to his website. Which can lead to folks discovering CJ long after that article is published.
- He’s either already written the content, or is writing something he can send to his audience anyway. There’s no duplicated effort here.
- More subscribers. Since these kinds of articles are exactly what he writes on his own site, when someone gets to the bottom and thinks “I really like that guys dad jokes”, they see that link over to Mostly Metrics, and wham – CJ has a new subscriber.
He’s getting paid to write his own content, that subscribers are paying to read, and that the brand is also paying you for?
Chef’s kiss.
Okay, so why in the world would a brand do this?
Well, they need content for their website too. But oftentimes the content strategy for a B2B SaaS is pretty low priority. And their customers don’t want to read articles all the time where they are just tooting their own horn.
It’s super valuable for them to have an outsider write something that’s not as biased.
I have a feeling they really enjoy this method of working with him.
While he started offering these posts for free, now he charges $5-$10k per sponsored post.
The triple stack approach:
- He’s getting paid by sponsors
- He’s getting free distribution to another audience
- He’s getting content he can share to his readers (who are also paying him)
Bing. Bang. Boom.
5. Recommendation Swaps 🔄
Kit, Beehiiv, and Substack all allow you to recommendation other creators after someone signs up for your newsletter.
And it’s a method a number of creators are using to grow their newsletter these days. CJ is no different. But the way he’s approached finding people to swap with is really interesting.
He essentially networked his way into getting recommended by bigger creators. How?
Well let’s back up a bit.
Mostly Metrics has 3 different types of readers:
- Younger professionals who want to look smart sends his content to their boss
- CFOs sending the content to their team
- VC’s who send it to their portfolio companies
CJ would find partners who have at least one of these three potential readers. And in the early days, he chose that third bucket and started networking with a few people who had VC’s in their audience.
But how do you network with people you don’t really know?
Instead of just DMing people asking to recommend one another, he asked to jump on a call.
After chatting for 30-60 minutes, you get to know someone much better than just through their online persona. So it became more of a friendly thing instead of a transactional thing.
And this gave him a leg up because his content was already good. They’d be much more willing to swap recommendations with CJ because the content was good and he built a friendly relationship with him.
One of those people had a group of folks they were recommending and brought him into th efold.
This might seem simple, but most creators don’t do this. They just recommend someone and hope they see it and recommend them back. Or they DM people and say “hey do you want to swap recommendations?”
It does exactly leave you feeling happy about the transaction.
Here are some of the people CJ has done swaps with are:
- The Product Compass
- Data-driven VC
- Growth Unhinged
- Clouded Judgement
- Dan Hock’s Essays
These all have adjacent audiences, but are not direct competitors, which is important for a successful swap like this.
Bonus: Free to Paid Subscribers
Running a paid newsletter seems pretty tough.
It’s hard to get people to go from reading your content for free, to turning around and paying to read the content.
Here are some things I’ve seen CJ do that I wanted to include here for you.
Juicy Lead Magnets
CJ creates templates and downloadables that you can only get if you’re a paid subscriber. So he’ll put them after the paywall in the article.
This is essentially a content upgrade where the article talks about this topic and shows you how to do something, but then offers you a done-for-you template if you upgrade.
If you’ve read the whole article and resonate with it, this is a perfect place to put that upsell/paywall option to entice people to sign up.
Super smart way to get some extra subscribers.
Mostly Equity
CJ also built a tool to help you understand if you’re getting paid enough in overall compensation, not just salary.
This tool is only for paying subscribers, so of course I paid to check it out. You give the tool a bunch of information and then it spits out this long report helping you negotiate a better salary and compensation.
The report it generates is robust and helps with negotiation tips, and gives you a full picture of what to think about.
I didn’t understand much of it, but I’m sure it’s helpful if you’re in that situation 🙂
Pass the Regret Test
Jay Clouse talks a lot about making sure people who buy from you pass the regret test immediately with great onboarding.
And CJ does a bang up job of this.
As soon as you pay to become a paid subscriber, you get this amazing welcome email:
Between the GIFs, references to Breaking Bad, and the Miller Lite comment at the end, you’re going to be entertained in one way or another.
CJ is infusing his personality into this in a number of places. And that’s why I said in the beginning of this deep dive that his growth has a strong foundation of dad jokes and personality.
And having content your audience loves and can relate to is a huge piece of any growth story.
Remember to have fun with your work, it’ll show through for your audience and build a strong foundation for the newsletter.
Make sure to subscribe to Mostly Metrics and tell CJ you enjoyed his story over on LinkedIn.
If you liked this, you might enjoy the two deep dives I wrote on Lenny Rachitsky:
- Lenny’s overall growth story
- A more specific deep dive into Lenny’s paid newsletter
