AP Business Exam Prep logo APBusinessExamPrep.com
AP Business Case Study · Unit 2, Task 7

Duolingo: How a Pushy Owl Became a Marketing Machine

🛠️ Skill Builder
Unit 2 · Promotion and Marketing

A real-company case study for Unit 2, Task 7 of AP Business with Personal Finance, written in the same format as the course's business cases. Read the case, answer each question on your own, then open the sample answers to check your thinking. Facts are current as of October 2026, and every source is listed at the bottom.

The Case

Unit & taskUnit 2, Task 7: Promotion and Marketing
Topic2.7
Key peopleLuis von Ahn (Co-founder and CEO); Zaria Parvez (Social media manager whose TikTok videos of Duo drew attention starting in 2021 (senior social media manager by 2025)); Katherine Chan (Marketing director who led social media (as of 2023))
Case years2011–2026 · Evaluation case
Key questionHow did Duolingo use social media, a memorable mascot, and in-app digital tools to promote its app and build relationships with learners, and what risks came with that approach?
Business Canvas componentsCustomer, Market
Snapshot
  • Business: Duolingo, a learning app best known for its language courses
  • Industry: Education technology
  • Founded: 2011, by Luis von Ahn and Severin Hacker
  • Headquarters: Pittsburgh, Pennsylvania
  • Key people: Luis von Ahn, co-founder and CEO; Gillian Munson, CFO
  • Ownership/Status: Public company (Nasdaq: DUOL)

A Free App and a Green Owl

Duolingo grew out of Carnegie Mellon University in Pittsburgh, where computer science professor Luis von Ahn and Ph.D. student Severin Hacker set out to build a free way to learn languages. The company was founded in 2011, and by June 2012, when Carnegie Mellon announced the free Duolingo.com website, more than 100,000 people had already used a test version. Its stated mission is to build the best education in the world and make it available to everyone. Courses are free. Learners who want an ad-free experience and extra features can pay for a subscription such as Super Duolingo, or Duolingo Max, a higher-priced tier launched in 2023 with features powered by generative AI.

Duolingo also has a mascot: Duo, a green owl created as the company’s logo in 2011. Over time, Duo became much more than a logo. Duolingo’s daily practice reminders had a passive-aggressive tone, and users started joking online about the pushy owl. Instead of ignoring the jokes, Duolingo built on them.

Growing Through Buzz, Not Big Ad Budgets

Duolingo did not build its audience mainly by buying ads. In its 2024 annual report, the company said it had grown primarily through word of mouth and brand buzz rather than paid user acquisition. That year it spent $90.5 million on sales and marketing, about 12 percent of its $748 million in revenue. Its official social media accounts had generated more than 10 billion impressions.

TikTok became the center of that buzz. Videos of a chaotic, passive-aggressive Duo made by social media manager Zaria Parvez began drawing attention in 2021. In 2023, marketing director Katherine Chan told Fast Company that a significant amount of Duolingo’s user growth came from people seeing the brand on TikTok and that the team could go from an idea to a posted video in about 30 minutes. Duolingo also ran separate social accounts in countries such as Japan, India, Germany, and Brazil, adjusting Duo’s personality for local audiences.

Reminders and Streaks

Duolingo’s promotion doesn’t stop on social media. The company also sends learners personalized emails and push notifications, including daily practice reminders. In a 2020 research paper, Duolingo researchers Kevin Yancey and Burr Settles described a computer program that chooses which reminder message each learner receives from a set of written templates, while avoiding messages the learner has seen recently. The program counts a reminder as a success if the learner completes a lesson within two hours. In a two-week experiment, the new system raised daily active users by 0.5 percent and new-user retention by about 2 percent compared with the old approach. The system was sending millions of reminders a day.

Those reminders protect a learner’s streak, the count of days in a row that the learner has practiced. Duolingo builds game-like features, such as points and streaks, into the app and has run thousands of A/B tests to improve them. At the end of 2024, about 32 million daily active users had a streak of seven days or longer, and about 10 million daily active users had streaks of 365 days or more.

The Day Duo “Died”

On February 11, 2025, Duolingo announced that Duo was dead. Fans soon learned the owl had supposedly been hit by a Cybertruck. The app icon changed to show Duo with crossed-out eyes, and Duolingo posted a fake press release and videos, including one of Duo’s coffin being loaded onto a truck. The story spread across Duolingo’s 13 localized social media accounts, along with localized ads and features inside the app, and the company released limited-edition Duo plushies in coffin-shaped packaging. Then Duolingo gave fans a way to bring Duo back: a web page tracked the experience points (XP) learners earned, with a shared goal of 50 billion XP. Each lesson was worth 20 to 35 XP. Exactly two weeks after his “death,” Duo returned.

Fast Company reported that the campaign earned about 1.7 billion social media impressions in roughly two weeks. Duolingo’s goal had been 70 million, and its biggest earlier campaigns had reached about 100 million. Fans created about 160,000 posts and videos of their own. In the first quarter of 2025, Duolingo averaged 46.6 million daily active users, up 49 percent from a year earlier, and the company later said that quarter benefited from its Dead Duo campaign.

Backlash, Then More Growth

Social media can also turn against a brand. In spring 2025, von Ahn posted a memo on LinkedIn about Duolingo’s growing use of AI. It said the company would phase out human contractors, look for ways to use AI in hiring and performance reviews, and add new employees only when a team could not automate more of its work. Many people posted angry comments on Duolingo’s TikTok videos. In May 2025, over a weekend, the company removed all of its posts on TikTok and Instagram and went silent on its social channels; a spokesperson said Duolingo was experimenting with silence. On May 20, it returned with a strange video of a person in a three-eyed Duo mask complaining that a single post about AI had made everything fall apart.

Duolingo’s latest results show its audience still growing. In the second quarter of 2026, it averaged 58.7 million daily active users, up 23 percent from a year earlier, and it had 12.7 million paid subscribers. Revenue rose 18 percent to $298.5 million. Its social accounts were earning more than 1 billion organic impressions each quarter, and the company said it now works with hundreds of creators around the world. In China, Indonesia, and India, about two-thirds of its social impressions came from influencer content. Duolingo also said it was growing more confident that paid performance marketing could become a meaningful driver of long-term growth. In June 2026, a one-time Streak Revival event let eligible learners restore their longest-ever streak, and 15.4 million learners did. The company has set a goal of reaching 100 million daily active users in 2028 and planned to report third-quarter 2026 results on November 3, 2026.

Exhibit 1: Duolingo key results by quarter
QuarterDaily active users (average)Monthly active usersPaid subscribers (end of quarter)Revenue
Q1 202546.6 million130.2 million10.3 million$230.7 million
Q2 202547.7 million128.3 million10.9 million$252.3 million
Q1 202656.5 million137.8 million12.5 million$292.0 million
Q2 202658.7 million140.6 million12.7 million$298.5 million

Source: Duolingo shareholder letters for the first and second quarters of 2026, which report each quarter alongside the same quarter of 2025.

Reading Questions

These are the same for every case. They check that you caught the basics before you analyze.

1. Which business does this case feature, and what product or service does it provide?
The case features Duolingo, a Pittsburgh-based company whose app teaches languages for free. It earns money from paid subscriptions such as Super Duolingo, which removes ads and adds features, and Duolingo Max, a higher-priced tier with generative AI features.
2. Who are the key people named in the case, and what roles do they play? Which other stakeholders — individuals or groups — have an interest in the business?
Luis von Ahn is Duolingo’s co-founder and CEO; he co-founded the company with Severin Hacker and later posted the memo about relying on AI. Zaria Parvez made the TikTok videos of Duo that drew attention starting in 2021, and marketing director Katherine Chan led social media in 2023. Researchers Kevin Yancey and Burr Settles designed the system that picks reminder messages. Other stakeholders include learners (free users and paying subscribers), contractors affected by the AI decision, social media followers and creators, employees, and shareholders.
3. Identify an opportunity and/or a challenge the business faces in this case.
One opportunity is Duolingo’s huge organic reach: its social accounts earn more than 1 billion organic impressions a quarter, and the Dead Duo campaign reached about 1.7 billion impressions in two weeks. Another is expanding into paid performance marketing and creator partnerships. A challenge is that social media can turn against the brand, as it did after the 2025 AI memo, when Duolingo removed all its TikTok and Instagram posts. Another challenge is turning free users into paying subscribers.

Practice Questions

These apply the Unit 2 concepts from Task 7 to the case, in the style of AP free-response prompts.

1. Identify two promotional tools Duolingo used in its Dead Duo campaign, including at least one digital marketing tool, and evaluate how successful the campaign was using data from the case.Topic 2.7 · LO 2.7.A
Duolingo used digital marketing, posting videos and other content about Duo’s “death” on its 13 localized social media accounts and changing its app icon to show Duo with crossed-out eyes. It also used media advertising, running localized ads to spread the story in different countries. The campaign was very successful at building awareness: it earned about 1.7 billion impressions in two weeks, about 24 times its goal of 70 million (1.7 billion ÷ 70 million ≈ 24), and fans created about 160,000 posts and videos of their own. It also pushed customers to act, because fans had to complete lessons to earn the 50 billion XP needed to bring Duo back, and daily active users grew 49% in that quarter, which Duolingo said benefited from the campaign. One limit of this evaluation is that impressions are not the same as paying customers, so Duolingo should also check whether the new and returning users became subscribers.
2. Explain how digital tools such as push notifications and A/B testing have changed the way Duolingo interacts with its customers compared with traditional advertising.Topic 2.7 · LO 2.7.B
Traditional advertising sends the same message to a large audience and is hard to measure, but Duolingo’s push notifications reach each learner individually inside the app every day. Duolingo’s system chooses which reminder each learner receives and avoids repeating recent messages, so the communication is personalized. Because the result of every reminder can be measured, by whether the learner finishes a lesson within two hours, Duolingo can test versions against each other and keep the ones that work. In a two-week A/B test, the new system raised daily active users by 0.5% and new-user retention by about 2%, which adds up when millions of reminders go out each day. As a result, the relationship becomes a data-driven, two-way exchange in which each learner’s behavior shapes the next message.
3. Describe the purpose of Duolingo’s streak feature as a way to build customer relationships. Then use Exhibit 1 to calculate the percentage change in paid subscribers from Q2 2025 to Q2 2026, and explain how stronger relationships can affect customer lifetime value.Topic 2.1 · LO 2.1.C
The streak’s purpose is to build a daily habit and a sense of commitment, so learners keep coming back instead of drifting away; at the end of 2024, about 32 million daily active users had streaks of a week or longer. Paid subscribers grew from 10.9 million to 12.7 million: (12.7 − 10.9) ÷ 10.9 ≈ 16.5% (Duolingo reported 17% using unrounded numbers). When learners stay engaged longer, more of them have time to see the value of a paid subscription and keep paying for it, which raises customer lifetime value (CLV). Loyal learners who recommend the app also help lower customer acquisition cost (CAC), which fits Duolingo’s statement that it grew mainly through word of mouth. The 2026 Streak Revival, in which 15.4 million learners restored streaks, shows Duolingo treating the streak as a relationship worth protecting.

Discussion Questions

Talk these through with a partner or your class. There's more than one good answer, so back yours up with evidence from the case.

  1. Duo’s reminders became famous for their passive-aggressive tone. Where is the line between a funny reminder that helps a learner and a message that manipulates or annoys customers?
  2. After the backlash to the AI memo, Duolingo deleted its TikTok and Instagram posts and went silent. Was that a smart response? What else could the company have done?
  3. Duolingo said it grew mainly through word of mouth, but in 2026 it said paid performance marketing could become a meaningful growth driver. Why might a business add paid promotion after years of organic growth?
  4. Which digital tool do you think contributed most to Duolingo’s growth? (a) TikTok content featuring Duo, (b) push notifications, (c) streaks, (d) the Dead Duo campaign. Support your choice with evidence from the case.
  5. Could a “dead mascot” stunt work for another brand you know? What would make it succeed, and what could make it backfire?

Application Activity

Pick a product or app you use regularly. Design a one-week mini-campaign for it that uses at least two promotional mix tools, including at least one digital tool (for example, a short-form video, a push notification, or an email). Identify the goal of the campaign and one number you would track to judge whether it worked.

Key Takeaways

  • A marketing campaign works best when it is coordinated across tools. The Dead Duo campaign combined social videos, a fake press release, localized ads, merchandise, and a challenge that required completing lessons, and it reached about 1.7 billion impressions against a goal of 70 million.
  • Digital tools turned promotion into a two-way, measurable relationship. Duolingo personalizes push notifications, tests them with A/B experiments, and tracks results such as daily active users and retention.
  • Building relationships, not just awareness, keeps customers coming back. Streaks and reminders give learners a reason to return daily, which supports subscriber growth and customer lifetime value, but a brand’s social voice can also turn against it, as the 2025 AI backlash showed.

Use it in your Business Canvas Project

For your Business Canvas marketing campaign, choose one digital tool your target customer already uses and plan how you would measure its results, such as views, sign-ups, or repeat purchases. Add one relationship-building feature, like a reward for coming back, to raise customer lifetime value.

For Teachers

Opening activity: Ask students to raise a hand if they have ever received a notification from an app that made them open it. Have a few students share the message they remember and why it worked or annoyed them. Explain that the case follows a company that turned reminders, a mascot, and social media into the center of its promotion.

Tip: “Print case” prints the case and all questions with the sample answers hidden, so it works as a student handout.

Sources

  1. Duolingo, Inc. Form 10-K for the fiscal year ended December 31, 2024, Duolingo, Inc. (SEC filing), 2025-02-28
  2. Duolingo.com Users Will Translate Web As They Learn a New Language, Carnegie Mellon University (press release), 2012-06-19
  3. Why Gen Z is obsessed with the Duolingo Owl, Fast Company, 2023-10-08
  4. A Sleeping, Recovering Bandit Algorithm for Optimizing Recurring Notifications (KDD ’20), Duolingo Research (Kevin P. Yancey and Burr Settles), 2020-08
  5. “Dead the sh*t out of it”: How Duolingo scored its most viral hit ever by murdering its mascot, Fast Company, 2025-04-10
  6. Duolingo deletes all its TikTok videos after AI backlash—and then returns with a strange message, Fast Company, 2025-05-20
  7. Duolingo Reports Second Quarter 2026 Results (press release), Duolingo, Inc., 2026-08-05
  8. Duolingo Q1 2026 Shareholder Letter, Duolingo, Inc., 2026-05-04
  9. Duolingo Q2 2026 Shareholder Letter, Duolingo, Inc., 2026-08-05
  10. Duolingo to Announce Third Quarter 2026 Results on Tuesday, November 3, 2026, Duolingo, Inc. (news release), 2026-10-08
All Case Studies Review Unit 2 Practice Questions

This case was written for educational use from the public sources listed above. Duolingo did not review it and is not affiliated with this site; company names are trademarks of their owners. This resource is independent and not affiliated with or endorsed by College Board.