TikTok + Duolingo: An Unexpected Product Growth Loop
Hiya 👋,
End of the year is almost here! While we’re all preparing up for a well-deserved break and pondering those New Year’s resolutions, Duolingo feels like the perfect company to talk about in this newsletter.
After all, learning Spanish will definitely make its way onto my resolutions list for the sixth year in a row 🥸. (It usually only works out un poquito)
This time, let’s explore one of Duolingo’s most fascinating growth loops.
🥕 Fun fact before we start: Did you know why Duolingo’s owl is green? 🥕
In the early discussions about the brand’s color, Duolingo’s co-founder Severin Hacker said, “Anything but green”. He REALLY doesn’t like the color. The team decided to troll him a bit - and so green it is! Source
Duolingo’s co-founder Severin Hacker is not impressed by Duo’s brand color
TikTok + Duolingo: An Unexpected Growth Loop
Let’s be honest: when you think of product growth loops and retention strategies, TikTok doesn’t exactly make it to the top list. But Duolingo is here to prove us wrong.
In a very short time, they grew their TikTok following from 50k to 8M with one viral video after another. And the best part? This wasn’t just about going viral - it had everything to do with the product.
Here’s how it went:
The Duo team asked themselves, “What are our users doing when they’re not completing their daily lessons?” A standard competitor analysis might suggest they’re learning languages elsewhere - like other apps, private tutors, or evening classes. But deep down, we know that’s not it. (Because, let’s face it, we’ve all been there.)
We skip our lessons because we’re doom-scrolling on social media.
The Duo team realized: if TikTok is where their users are, then TikTok is the competitor they need to beat.
Using TikTok as a Notification Tool
And so the unhinged green owl came to be. "Lovingly" reminding you to do your daily lesson while you procrastinate on TikTok.
Instead of going the obvious route, teaching language basics through short clips, Duolingo’s TikTok videos focus on one goal: dragging you back to the app.
Here’s the simple yet brilliant growth loop:
New user downloads Duolingo.
They complete their daily lesson, feel accomplished, and go about their day.
Later, they pick up their phone and start doom-scrolling TikTok.
A Duo video pops up, reminding them (in its signature, mildly threatening tone) to complete their lesson.
Existing user: Feeling guilty, they return to the app (back to step 2).
New user: Sparks curiosity about the app, downloads Duolingo (back to step 1).
This loop makes TikTok both a user acquisition tool and a retention strategy. Genius, right?
Duolingo’s viral product growth loop - using TikTok as a replacement for in-app notifications
How Duolingo Got Here: The Journey Before TikTok
When Duolingo started focusing on social media, they already had a solid foundation. Socials didn’t create their success from scratch - it just gave it the push it needed. After all, you can’t start a fire without a spark.
Here’s a quick look at what laid the groundwork for Duolingo’s growth before their TikTok fame 👇
1️⃣ Five years of product development, Zero marketing
Duolingo didn’t need flashy marketing in the early days. With $3.3M in Series A funding (thanks to Luis von Ahn’s reputation - he’d already sold two companies to Google, including ReCaptcha), they focused entirely on building a great product. The gamification idea? Genius. People loved it, and word of mouth did the rest.
When I say “zero marketing,” that’s not totally true. They didn’t spend money on ads, but PR played a big role. And it worked.
2️⃣ Monetization struggles
Initial idea to monetize was Crowdsourced translations. Users would translate bits of text while learning, and Duolingo would sell that work. Solid plan… until machine translation got better and made it irrelevant.
They didn’t want to clutter the app with ads, but eventually, the team gave in and introduced a single ad after each lesson—skippable after 5 seconds. Not too intrusive, but it worked! This tiny change converted enough people to Duolingo Plus. Fast forward to now: 8% of monthly users subscribe to Plus, and those users bring in 80% of their revenue.
3️⃣ PR as a growth hack
One of the most underestimated channels to gain traction for startups is PR. Yet that's where Duolingo generated majority of its early traffic. Luis von Ahn’s 2011 TED Talk about democratizing language learning brought in 300,000 signups during the beta phase. They also secured coverage in major publications like TechCrunch or The New York Times that helped continue the momentum.
If you haven’t watched TED Talk about Duolingo, it’s worth a look: Luis von Ahn’s TED Talk.
4️⃣ Blunt notifications that became memes
You know those blunt, mildly passive-aggressive notifications from Duo? Turns out, they weren’t part of some big strategy. They just… happened.
At one point, the team tested stopping notifications for inactive users. But as they were about to stop them they though why not to tell users we'll do that? And so they added the message: “These reminders don’t seem to be working. We’ll stop sending them for now.” A very straightforward engineering approach to UX copy.
People loved it. Memes about the “scary green owl” exploded, with jokes about Duo knocking on your door if you missed a lesson.
As any other smart team, Duo doubled down on what works and started adding more mean notifications that only fuelled more memes.
5️⃣ Shifting Focus to Social Media
By 2020, Duolingo decided to shift focus to social media. They leaned into the Duo memes and created low-budget, relatable content featuring the unhinged green owl we all know and sometimes fear. The result? From 50k to 5M followers in a year. Their secret? Humor, relatability, and that “do your lesson or else” energy that we couldn’t get enough of.
Sometimes, happy accidents lead to massive growth. So, the next time you’re tempted to rewrite an engineer’s copy, think twice—you might just be onto something big. 😁
