$21,000 per year only from paid subscription!
The Rotten Apple by Karen Constable
Newsletter Circle is your go-to source for building a successful newsletter business through a paid subscription.
👋 MEET THE CREATOR OF THE WEEK
is a food industry expert with decades of experience in food safety, quality assurance, and product development across multiple sectors.
In 2021, she leveraged her expertise to launch The Rotten Apple on Substack—a bold, ad-free newsletter focused solely on delivering value to her readers.
Today, she holds a bestseller badge on Substack and generates over $21,000 annually through paid subscription.
She has over 200 paid members out of 3,000 subscribers. And this means 6% conversion rate which is higher than many Substack newsletters!
Beyond her food industry insights, Karen also runs PubStack Succes where she shares strategies on how to grow and monetize a Substack newsletter with 4,000+ subscribers. Her firsthand experience even led her to write a book called “How To Make Money With Substack” offering a roadmap for aspiring creators.
In this interview, you will find valuable insights such as:
Why she started a newsletter as a food industry expert
How she reached over 3,000 subscribers
How she generates $21,000+ per year solely from paid subscriptions
How The Rotten Apple has impacted her professional journey
Enjoy!
🏷 NEWSLETTER IDENTITY CARD
⚒️ TOOL STACK
ESP: Substack
Writing: MSWord
Curation & Note taking: MSWord
Audio Editor: Auphonic – an audio processing app for podcasts and youtube audio clips
🥁 START
How and why did you start The Rotten Apple in the first place?
I started it to be a new income stream that doesn’t involve swapping time for money… when I get more subscribers, I get more money but don’t need to do more work. Different from consulting work where you are swapping time for money. Absolutely love the scalability of it.
🚀 GROWTH
Which strategies did you use to grow over 3,000 subscribers?
I’ve used the same strategies since day one:
Publishing consistently
Keeping my promises to my readers
Publishing quality content
Meeting new people on social media (primarily LinkedIn) so they can get to know and trust me, which makes subscribing a no-brainer
What’s changed is I ditched social media platforms that weren’t converting after around 6 months (I only had 800 subs after 6 months).
You bring your subscribers to your newsletter from LinkedIn, Youtube, and an SEO-optimised website. What did you do best to be successful in turning followers/visitors into subscribers on that channel?
“LinkedIn and my website are the best. On the website, I have a pop-up which invites people to hear from me every week, with a space to sign up. On LinkedIn, I focus on showing people my expertise so that when I share something from my newsletter they are excited to click through to check it out. LinkedIn groups are good too. “
— Karen Constable, The Rotten Apple
Of course, when people from LinkedIn arrive at that post, you need to also have a great intro and CTA above the fold to encourage them to subscribe.
Regarding growth efforts, what would you do differently if you had a chance to start over?
I wouldn’t change anything. The extras I have added to the publication over the years – the stuff that gets readers really excited to convert to paid subscribers – would have been way too overwhelming for me to do in the beginning.
“I encourage the new Substackers I coach to go at a speed that feels manageable to them, and to get comfortable with each new thing before trying another ‘growth hack’. Burn out is a huge risk and it’s important to protect yourself from it when you’re a solo creator. “
— Karen Constable, The Rotten Apple
💸 MONETIZATION
You started your newsletter in 2021 with no audience, and now you make $20,000 per year from paid subscriptions. When did you start paid subscription? What are your strategies to convert free subscribers into paid ones?
I was around 6 months in and had 800 subscribers when I launched paid subscriptions. Currently, I have more than 200 paying subscribers.
My paid subscribers get access to reports, supplements, indexes and recordings that free subscribers don’t get. Some pay because they really need those things, but most pay mainly to show appreciation for my efforts.
It’s worth noting that in a B2B newsletter like mine, where readers can get their employer to pay the subscription, you have to give extra benefits to paying subscribers, so they can justify the cost to their boss.
What are your biggest learnings when applying for a successful paid subscription?
I needed to try new benefits, formats and CTAs multiple times to get to a 6% conversion rate. If you reach a plateau in conversions soon after launching paid it’s probably because all your mega-fans have signed up but no one else is interested. Try adding more benefits and/or changing your messaging to encourage people who are not mega-fans to also upgrade.
You wrote in your LinkedIn profile “The Rotten Apple contains no endorsements, no promos, no ads. Ever.” for your newsletter. What are the main reasons for this decision? How does it affect your newsletter business?
I compete for inbox space with hundreds of other industry newsletters, all vying for the attention of my audience. The ads and promos in those newsletters are next level over the top. Having no ads is a key point of difference and gives me a huge advantage over those competitors. Because I don’t promote my other work my audience can be confident that when I share something with them it’s 100% for their benefit, not for some hidden promotional reason. Also, when I tell them I need their support they know I’m 100% authentic about that too.
📌 IMPACT & LEARNINGS
How did building The Rotten Apple newsletter contribute to your life professionally and personally?
I have met fantastic food safety professionals from all around the world and picked up new consulting clients through these new connections. I travelled to a big conference in the US using subscription income in 2024 and had a ball. And then I wrote about what I’d learned at the conference in my newsletter. It’s been awesome.
Probably my favourite outcome is I now get to help other creators by teaching them what I have learned about succeeding on Substack.
“In fact, I just published a book called How To Make Money With Substack under a pseudonym Karen Cherry and it’s doing well with dozens of 5 star reviews on Amazon!”
— Karen Constable, The Rotten Apple
What would you do differently if you had a chance to start over The Rotten Apple?
As above, I wouldn’t do much differently. I do know now that revenue grows faster when I spend a little time on LinkedIn every day, so I would try to be more consistent with that.
What would it be if you had the right to give one piece of advice to aspiring newsletter creators?
These days I spend a small part of every week doing exactly that: giving advice to aspiring newsletter creators, with my free newsletter PubStack Success. I absolutely love working for this other audience, they are so different to my food safety audience, and it’s super fun being able to encourage other creators and share all the secrets I’ve learned in the past 3 years.
I’ve also got perspectives on B2B newsletters that other ‘Substack Experts’ don’t have, which my coaching clients really appreciate.
3 Popular The Rotten Apple Issues
Where to find Karen Constable
“PubStack Success” Newsletter free newsletter by Karen on Substack growth
“How To Make Money With Substack” book by Karen
ICYMI: The Latest Newsletter Circle Issues
Thanks for reading, and feel free to reply if you’d like to connect!
See you next Sunday.
Ciler
The goal.
Thanks for sharing, Ciler!
Beautiful, Karen and Claire! Thanks for the background and insights into one of my favorite Substack authors' journey!