Grow: How Katelyn Jetelina turned a side hustle into a safety net
The Grow interview series is designed to share the nuts and bolts of how writers have gone independent and grown their audiences on Substack. It has been lightly edited for length and clarity.
We invited
, who writes (YLE), to share her advice on growing her Substack from scratch to a subscriber base in the hundreds of thousands. Katelyn, an epidemiologist, data scientist, and senior scientific consultant to organizations such as the CDC, started the newsletter in 2020 to update students, faculty, and staff about developments in the pandemic. Over 36 months, it became renowned for translating public-health science into accessible and actionable posts, with a mission to make science available to everyone.In this interview, Katelyn details how her newsletter went from a side hustle written after her children’s bedtime to a safety net allowing her to quit her day job and focus on public-health communications full-time.
What’s your Substack about in one sentence?
Translating public-health science for everyday use.
Who reads your publication?
I always thought I was talking to Joe on the corner. But after sending out a survey (I got 77,000 responses), I found that my audience is trusted messengers—scientists, pastors, school boards, engineers, physicians—that diffuse YLE information further into their networks. I’m just a node in a grassroots information-diffusion network.
Read more: YLE has reached 126 countries. What’s next? Survey results
What do you uniquely offer readers?
One thing I found throughout the pandemic was that scientists are generally very bad at speaking in plain language. During an emergency, this hindered the response and cost lives. So my unique contribution is processing and translating the knowledge for easy, digestible, and actionable items for the public during a firehose of information.
What’s your content strategy?
Schedule: Publish 2x weekly.
Types of posts: For the first two years it was purely Covid-19 stuff. I’m now experimenting with other topics, like gun violence, vaccines, and reproductive health. I have many different post types—thought-leader pieces, guest authorships, interviews. It’s been fun to explore!
Format: A scientific communication publication in mass media once told me that people don’t read more than 1,200 words. So ever since then, I try to keep it to below 1,000 words per post. I also just read the book Smart Brevity, which has really transformed my writing style to more bullets, more pictures, more headlines. Bottom line is that I’m experimenting with long and short forms, with interviews and thought pieces. It’s a blast.
Why did you move from social media to Substack?
Back in February 2021, my accounts were hacked by anti-vaxxers. I quickly discovered that my content—my blood, sweat, and tears—was not owned by me. I was simply renting space from social media companies. It took an incredible effort to get my pages back. In fact, I don’t think I would have gotten them back if I didn’t have a friend who worked at Facebook headquarters. I needed to find a home in which I had almost complete control of my content.
Growth by the numbers
Started Substack: February 2021
Went paid: A few weeks after going live
Total subscribers: 190,000
Paid subscribers: ~10%
Meaningful growth moments
Getting started: Before Substack, I gained a ton of traction on Facebook and Instagram in 2020 when the pandemic was starting to really take hold in the States. I was writing YLE on social media but needed to find it a permanent home, so I thought of trying out Substack.
With each Covid-19 variant, you can see a noticeable uptick in subscribers. This first one was Delta.
This was a huge influx, when my Substack went viral regarding the Omicron variant.
There is no huge increase here, but it is a really important milestone, as it was the time I started branching out to other public-health topics.
Today: I’m in an experiment phase. This year is a critical time for YLE. My goal is to sustain interest in public health beyond a pandemic and beyond infectious diseases. I want to show people that public health touches our lives every day. If I can do that—show that it’s an invisible force working in the background—then maybe we can get more people interested in this field and ultimately support it.
How does your Substack fit into the rest of your professional and personal life?
This is my side hustle. It was something I wrote at night once I put my girls to sleep after working all day on the Covid-19 front lines. I still consider myself a scientist first and a communicator second, but I’ve fallen in love with writing. This summer I’ve given myself a few months off my “day job” after a grueling 3.5 years of the pandemic. I’m going to continue YLE during this “downtime” while I work toward a sustainable model for public health communications moving forward.
YLE provided me with a safety net. This allowed me to be more creative and more innovative, in a space that was far more fun, which supplemented my daily grind beautifully.
Eventually it allowed my family the opportunity to move back to California to be closer to family. It changed my life both personally and professionally.
Why did you go paid?
This was a super-hard decision for me. I think it was because I’m a woman, a scientist, and just trying to help during a really tough time in our history. Moreover, I strongly believe that science should be accessible and available to everyone. But throughout the pandemic, many people found my content useful and important, so they wanted to donate. I was also spending a lot of time with YLE, and it started coming at a cost that I needed to compensate. So I opened up subscriptions as a donation. Everything is still free.
How has using Substack impacted the way you engage with your area of professional expertise and the wider public?
It was an absolute game changer. Scientists, like myself, are usually confined to formal dissemination avenues to talk to other scientists—like conferences, publications, ResearchGate, etc. These are critical for science to move forward. However, what I think is equally important is a direct line from scientist to community. Scientists didn’t have an avenue to do that. A lot of the time we rely on mass media, which often introduces intrinsic biases. YLE created this direct line to the community. Critically, it allowed me to listen to the community too—listen to their concerns from a place of empathy. This drives my content, as opposed to what I think people need to know.
How do you balance your time between work as a data scientist and epidemiologist, family life, and writing on Substack?
Balance is something I struggle with on a daily basis. But I don’t think this is a unique experience. Being a working mom is a common struggle in the U.S. There is so little institutional and societal support to make this path easier. I truly believe we can “have it all” if we want, but it is sure hard a.f.
YLE provided me with a safety net. This allowed me to be more creative and more innovative, in a space that was far more fun, which supplemented my daily grind beautifully.
What is the sharpest piece of advice or insight you can offer other writers about growing a Substack publication?
Be consistent. Always show up. Let your voice and personality bleed through.
What advice have you received about growing your publication that didn’t prove to be helpful?
Everyone thinks that some content has to be for only paid subscribers. And maybe it does for some people, but I didn’t find the need. At least not yet. If people believe in your cause and you bring them something useful to their lives, there will be a lot of support.
Who’s another Substack writer you’ve turned to for guidance or inspiration?
My initial inspiration was
. Now my inspiration is all of the other scientists who are exploring this new terrain of communicating with the public.Throughout the pandemic, many people found my content useful and important, so they wanted to donate. I was also spending a lot of time with YLE, and it started coming at a cost that I needed to compensate. So I opened up subscriptions as a donation. Everything is still free.
Takeaways
You don’t have to share extra content to go paid. Subscribers will pay you to keep going, especially when your work offers collective impact or supports the public good, without necessarily needing extra perks or writing. Read more.
Know your readers. Katelyn sent out a survey and got 77,000 responses, allowing her to better understand who she is talking to and what lands. Read more.
Invest in your ownership. Unlike with social media, on Substack you always own your intellectual property, mailing list, and subscriber payments. You’re not at the mercy of the algorithm and hackers.
What questions do you have for Katelyn that we didn’t ask? Leave them in the comments!
To read more from this series on growing your publication, see our interviews with Rob Henderson, Tyler Bainbridge, Melinda Wenner Moyer, Leslie Stephens, Becky Malinsky, Tim Casperson, Marlee Grace, Gergely Orosz, Anne Kadet, Category Pirates, BowTiedBull, Justin Gage, Noah Smith, Carissa Potter, Jørgen Veisdal, Anne Byrn, Nishant Jain, Michael Fritzell, Glenn Loury, Erik Hoel, Jessica DeFino, Mike Sowden, Elizabeth Held, Jonathan Nunn, Polina Pompliano, Michael Williams, Judd Legum, and Caroline Chambers.
If you’re inspired by Katelyn and want to write on Substack, you can get going here:
Share this post