Why do I keep coming back to Duolingo?

Exploring Nir Eyal's Hook Model, I analyze how Duolingo uses its four stages to keep users engaged, raising ethical questions about user value in various industries.

Source: AI-Generated

So, I recently started the book 'Hooked' by Nir Eyal and at the same time I completed a 100-day streak on my Duolingo app.

Okay, so what? What's the correlation?

Turns out, Duolingo is a prime example of how companies use the Hook Model, a concept Eyal dives into in his book. I’m going to break down exactly how Duolingo applies this model, focusing on its 'Attention Economy' to keep us hooked.

Attention is the new Oil!

To kick off first - what's the Hook model?

The Hook model has 4 stages -The Trigger, The Action, The Variable Reward and The Investment.

I’ll be focusing specifically on how Duolingo uses the Hook Model, turning the theory into something tangible. While I’m zooming in on Duolingo, these stages can be found across many companies that leverage the same model.

1. The Trigger Stage: Passive Aggressive Notification: 

   A trigger is basically a nudge to action and can be external as well as internal. For instance, CTAs, the 'Buy Now' button and push notifications.

   • In Duo’s case, the 1st trigger is the app’s push notifications which have 2 variations - one it’s a playtone and the other is a sassy teenager who sarcastically teases your learning.

   • These notifications are sent exactly 24 hours after the last session based on the user’s pattern of learning. That is because if you were free at 9 pm yesterday, high chance that you will be free at 9 pm today. But Duo went one step ahead and found out the patterns of weekday vs weekend users’ learning. (Smart, right?)

   • And when there is no activity after 7 days even after the push notifications, Duo stops sending notifications but after the last notification which has highest retention metric - that notification is the “Guilt Triggering Notification” which is more like “These reminders won’t seem working. We’ll stop sending them from now”. This is more like our mom taunting us for not doing our work. These aggressive notifications got into the memes and the marketing team started using them for their promotions.

     
     

2. The Action Stage: 3-min Lessons to Lower Resistance

   This is where Duo pushes people to do a 3-minute lesson which is the bare minimum time-consuming task. Their lessons are designed in such a way that the least time taken to finish a single lesson is less than 3 mins.

   
   

3. The Variable Reward Stage: Gamifying Learning

   This is where addictive learning comes in. The notion behind this is - that when a subject is given a reward in a very unpredictable pattern (variable), then the subject will push itself and will do the task way more frequently in expecting and in anticipation of the unpredictable reward.

   
   

   In Duolingo’s case, these variable rewards come in the form of league matches, daily gems, and leaderboard rankings, all of which inject a sense of competition and achievement into the learning process. This gamification creates an addictive loop where users strive to maintain or improve their standing, not just for the sake of learning but to achieve these in-app rewards.

   
   

4. The Investment Stage: Why You Won’t Quit

   Lastly, Duolingo capitalizes on the concept of investment, which is the effort a user puts into an activity, making them less likely to abandon it. One of Duolingo’s most effective tools in this category is its streak feature, which tracks how many consecutive days a user has engaged with the app.

   
   

   For many users, the streak itself becomes more valuable than any tangible reward. In fact, as of 2023, over 3 million users achieved a streak of 365 days or more. This is similar to the effect seen in social platforms like Snapchat, where the effort put into maintaining a streak outweighs its actual value. The streak, in essence, becomes the reward, encouraging users to return to the app day after day to maintain their progress.

So, this is how Duolingo achieved its Attention Economy with its users. However, the same Hook Model blueprint is used by many other platforms, which raises important questions—especially when these platforms neither create meaningful value nor genuinely benefit their users.

For instance, dating apps like Bumble, and Tinder, and social media platforms like BeReal, Snapchat, etc., use follow the same model. Each app guides users through the four stages of the Hook Model, making it incredibly hard to simply walk away.

Is it that only tech companies use the Hook model?

Surprisingly No.

A variety of industries, from food and beverage to fitness. Here are some examples:

• Starbucks: Habitual Coffee Purchases

  
  

• Nike & Strava: Building Fitness Habits

  
  

• McD & Dominos: Repeat visits and purchases

• Temu: Making E-commerce shopping Habitual

But this leads to an interesting ethical debate—why do we view Duolingo differently from these other apps when they all use the same psychological tactics?

I believe it comes down to whether or not the company creates genuine value for its users. If an app improves lives in some meaningful way, as Duolingo does with education, then I think it's justified.

What do you think about this? Comment down your thoughts and I am so curious to have a healthy debate.