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Why Is Duolingo So Crazy?
Studying Duolingo's successful commercialisation of language learning to $1BN ARR and world domination.
Olabinjo Adeniran
February 26, 2025
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Humanity is multilingual
The mythical story of the Tower of Babel explains the origin of a multilingual earth. In this story, humanity unites to construct a tower that reaches the heavens so they are not scattered across the planet. Yahweh (the creator) looks down upon humanity and realises they would achieve this feat and everything else they aspire to do. Yahweh believes this desire to be like gods is bad for humans and confuses their language. As a result of these language differences, there was conflict during the tower's construction, leading to their dispersion from Babel and scattering across the earth.
Numerous languages present a seemingly endless opportunity for language-learning providers in various forms. When I was growing up, there were many ways to learn languages that your parents didn’t speak - you had a teacher at school, you enrolled in a language class at a place like Alliance Française, watched a TV show like Dora the Explorer, or used a compact disc from a company like Rosetta Stone. Some students would combine multiple methods. For instance, I learned French through my teachers at school, watching a lot of TV5, and attending classes at Alliance Française.
The rise of the Internet began to change things as translation and language learning sites sprang up. When we completed our French assignments at school, I recall that we would input the answers into Babelfish and, later, Google Translate. Today, there are various ways to translate languages—tools like Google Lens, Google Translate, and Zoom make it easy to understand others. Yet, the fundamental human desire to listen, comprehend, and authentically connect remains strong.
Fun fact: Despite spending much of my life learning French, I visited a francophone country 7 years ago and struggled to speak the language.
Enter: Duolingo
Duolingo is one of several solutions for language learners. It is a popular gamified language-learning app that provides bite-sized lessons in various languages. It focuses on developing vocabulary and grammar skills through interactive exercises, including reading, writing, listening, and speaking.
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This growth case study will examine Duolingo’s successful attempt to dominate language learning and education. In recent years, the company has become associated with the most outrageous and eccentric marketing stunts, embedding itself into culture as it spreads its influence wherever you go. I aim to answer the question: Why is Duolingo doing this?
As always, feel free to skip to sections that interest you.
Table of Contents
Duolingo - Origin and Success
Founded in 2012 by Luis von Ahn and Severin Hacker, Duolingo is one of the most successful freemium apps globally. In 2021, Duolingo went public on the US-based NASDAQ stock exchange with 40 million active users. By the third quarter of 2024, it boasted over 110 million monthly active users (an impressive growth of 30M compared to the previous year) and annual revenue of over $500 million. Duolingo is the most popular app in the education category of apps, outshining language learning rivals like Babbel, Memrise and Busuu.
Duolingo is a Game
It’s important to shift Duolingo’s perception from a learning app in the edtech industry’ to a learning game’. The company has successfully built language learning into an endless game. The app features a tight retention loop with its gamified features - streaks, weekly competitions, and earning systems like gems, medals and experience points.
For this case study, it’s better to think about Duolingo as a game than to think about Duolingo as a learning product. The app has even built multiple character arcs into learning with main characters like Duo, Lily, Zari, Lin and Falstaff. These are typical features of a game.
However, this case study does not focus on Duolingo’s gamification tactics. You can read a detailed analysis of that here.
Duolingo is crazy
Because Duolingo is a game, it needs to be creative in its marketing tactics. Duolingo infuses its gamified app with a remarkably bold, astonishing global campaign featuring Duo, its prominent mascot. Duo began as an app companion designed to nudge users to complete lessons, engage in daily practice, or remember to maintain their streak. However, it has now become a tangible mascot that can appear anywhere. The mascot is the brand persona and is funny, annoying, sarcastic, silly, weird and creepy - Duo is so unique to the brand that it’s difficult to replicate by other learning apps.
Duolingo’s mascot exists because creativity is necessary - it needs to stand out. Duolingo is pushing the traditional boundaries of learning apps and expanding to become a gamified entertainment app.
The company is approaching this by commercialising its app and infusing it into everyday culture. It then ensures people keep using its apps—with gamification and retention features—while earning revenue via a paid product with even more features.
Here are some of Duolingo’s crazy stunts.
Duolingo at a Charli xcx concert.
@duolingo charli said “talk to me in french” and we listened 🗣️ #brat #sweattour credit: @Julia 💚 #charlixcx #troyesivan
Duolingo and Squid Game - this is their own song!
Duolingo is crazy on LinkedIn, too!
By creating a crazy brand and mascot, Duo, the company can appropriately insert itself into any conversation on the Internet, expanding its reach and acquiring more users for the app. The company has expanded its target audience from language learners to people who want to have fun in a game. Its entire online persona, mascot persona, and brand voice are geared towards entertaining the public and achieving maximum reach. There is a reason and method to its madness.
Duolingo’s business model
Now, let’s talk money. Duolingo is one of the apps operating in a freemium model. The app is free but has Super and Super Family modes. Duolingo monetises free users via ads, while its premium features contain no ads. These premium modes offer benefits like unlimited hearts when users make mistakes, skills practice tests, challenges, and no ads. Duolingo also earns income via translation services and standardised testing.
Duolingo’s revenue success
The company’s business model brings us to Duolingo’s money. It is a publicly listed enterprise that is mandated to publish its numbers.
In 2023, Duolingo increased its revenue by 44% to $531.1 million and was profitable, with a net income of $16.1 million. It ended 2022 with a loss of $59.6 million, so 2023 was a massive win for the company. While Duolingo hasn’t announced its fourth-quarter and full-year earnings for 2024, it’s posted an outlook and has released results for Q1-Q3 2024.
Duolingo’s gamification models are the source of revenue
Gamification is the core reason for Duolingo’s wild success. In an article in Lenny’s Newsletter, Duolingo’s Head of Product, Jorge Mazal (ex-Zynga), discusses increasing gamification to improve retention.
Armed with a short presentation I co-created with our chief designer, we were able to get just enough buy-in from the rest of the executive team to create a new team, the Gamification Team. The team consisted of an engineering manager, an engineer, a designer, an APM, and me.
But there was one small issue: we had no idea which incremental gamification mechanics would work for Duolingo.
Our team at the time was hooked on a game called Gardenscapes, a mobile, match-3 puzzle game similar to Candy Crush. This mobile game became our first inspiration.
Duolingo loops users’ data into the app as feedback, showing their progress, enabling them to compete with each other, or directing them to purchase a premium feature.
Here’s Jorge again talking about lessons from working on Zynga’s Farmville.
In FarmVille 2, competing in the leaderboard required completing additional kinds of tasks on top of the core gameplay. That was something that we purposefully left out. In the Duolingo context, more tasks would only add unnecessary complexity to language learning. We deliberately made our leaderboard as casual and frictionless as possible; users were automatically opted in and could progress to the top of the first league by merely engaging consistently in their regular language study. By keeping the game mechanic exciting, but making it simpler than in FarmVille 2, we felt like we had struck the right balance of adopting and adapting.
This leaderboard tactic would prove successful with Duolingo’s learners, improving retention and increasing time spent. If people keep signing up and learning, that can turn into billions of dollars in revenue.
The leaderboards feature had a huge and almost immediate impact on our metrics. Overall learning time increased by 17%, and the number of highly engaged learners (users who spend at least 1 hour a day for 5 days a week) tripled. At this time, we hadn’t yet figured out how to calculate statistical significance for CURR, but we saw that our traditional retention metrics (D1, D7, etc.) improved materially and with statistical significance. Going forward, the leaderboards feature became a vector for improving metrics, and teams continue to optimize the feature to this day. Also importantly, the leaderboard was the Retention Team’s first breakthrough!
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The future of Duolingo - Duo is alive!
We’ve discussed money and how Duolingo solves retention with gamified loops; let’s discuss the future and wrap this up.
While drafting this piece, Duolingo killed its mascot and launched ‘Bring Back Duo’, an in-app campaign to ‘revive’ its mascot. It successfully achieved that goal - with millions of users playing to earn over 50 billion experience points. Now that Duo is back, we can discuss the company’s future.
y’all really think i’d let a cybertruck take me out? #duolingohasrisen
— Duolingo (@duolingo)
1:15 PM • Feb 24, 2025
As a publicly listed company on the NASDAQ Stock Exchange, Duolingo has a $17BN market cap and a P/E ratio of over 200. However, it’s nowhere near where its investors think it should be. While Duolingo is a great company, its market cap and P/E ratio are far higher than those of comparable pure-play software companies in public markets. Its stock has also risen rapidly in the last year, showing signs of investor interest.
Duolingo must generate billions of dollars in annual revenue to justify its stock price and market cap. Here are my predictions for the company's future and its path to billions of dollars in yearly revenue.
Prediction 1: Beyond Languages: Music, Math and Others
In October 2023, Duolingo announced the addition of Math and Music learning to its app. As I mentioned earlier, there are only so many people willing to learn languages—there are numerous subjects and topics that Duolingo could develop. I predict that Duolingo will introduce more subjects, such as Science, Biology, Physics, Art, and History. Duolingo has the potential to teach anything it chooses. In my survey of Duolingo users, around 80% were unaware that the app hosts Math and Music lessons - so there’s a lot of revenue and usage opportunity here.
Prediction 2: More Apps
Duolingo has the opportunity to broaden its strategy and create more apps. Considering Duolingo as a gaming company suggests it could benefit from maintaining a diverse array of learning games apps in its catalogue. This approach would align Duolingo more closely with companies like King, Zynga, Ubisoft, Konami, and EA rather than with other educational app developers like Babbel, Busuu, and Memrise.
Prediction 3: More Features
Education is one industry where AI drives productivity and new product features. Duolingo has long relied on AI tools to build content for its users, and with the launch of OpenAI’s generative pre-trained transformer (GPT) model, it’s begun to do more.
Several Duolingo users have long expressed frustration about their inability to speak languages beyond the app’s content. Among actual language learners, this is a recognised issue with Duolingo that the company aims to rectify. In March 2023, it introduced new AI features in a subscription tier known as Duolingo Max. Built with OpenAI's GPT-4, Duolingo Max subscribers can engage in real-life conversations within the app while receiving real-time feedback on their language progress. By September 2024, it added another layer - video calls with Lily, one of the app's main characters.
Prediction 4: More Mascots, More Media, More Revenue
The Duolingo app features numerous characters, which the company has transformed into mascots with unique backgrounds and personas. While these characters are enjoyable for users, they represent intellectual property owned by the company, which can develop media based on this IP. By creating these characters, Duolingo now possesses intellectual property that could extend beyond its app; it could produce a film series, a television series—anything involving a cartoon character.
Duolingo has already begun implementing this idea by launching a plushie store where fans can purchase Duo, Zari, Falstaff, and Lily plush toys. Media is at the heart of Duolingo’s collaborative efforts—it’s partnered with Squid Game, The Teletubbies, and Barbie. This strategy is not unusual; gaming is a form of media, and Nintendo, the maker of Super Mario, has amassed $10 billion from licensing its characters.
Wrapping this up: So Why Is Duolingo Crazy?
Duolingo needs to set itself apart in a world with competing learning methods. It is on a different path from other education and learning providers by rethinking its app as a game, building characters with content, and rolling out consecutive marketing stunts. The company has expanded its addressable market and set its sights on total world domination, and its features, crazy tactics, and storytelling will get it there.
Because Duolingo has designed itself as a game and has become a media company, it needs to entertain the public. Many SaaS or commercial apps are not media companies and do not need to entertain this much. Sure, multiple brands could sponsor a Charli xcx concert or interact with Dua Lipa on Twitter, but the vibe will always be different.
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