5 Ways to Create Products that Stick Using Psychology

What you can learn from the book “Hooked” by Nir Eyal

Zoe Chew
7 min readMay 7, 2024

Note: This post is part of the Multi-Part Product Building Lessons series. You may also like my top-rated guides such as — Product Building Lessons, Minimum Viable Experiments, and Create Monetizable Products.

If you’re thinking about reading or already know about Nir Eyal’s book “Hooked,” this post will give you the main frameworks and takeaways for building habit-forming products. I’ll also share my own perspective on those principles, integrating Eyal’s frameworks, summaries, and lessons.

book review: Hooked by Nir Eyal how to build habit-forming products

Lesson 1: Understand the Habit Loop

The Hooked Model, created by Nir Eyal, expands on Charles Duhigg’s habit loop model, which consists of three components: cue, routine, and reward. The cue acts as a trigger that initiates a habitual routine, followed by a reward that reinforces the behavior.

If you’re coffee drinker, you can probably relate to this. The cue of waking up triggers the routine of brewing coffee, and the reward of enjoying its aroma and taste reinforces this habit, making it an essential part of your morning routine.

Eyal’s Hooked Model expands on this idea by introducing the “Hook Model,” a four-step framework consisting of Trigger, Action, Variable Reward, and Investment.

While both models share similarities in understanding human behavior and habit formation, the Hooked Model underscores the significance of user investment in reinforcing habitual behavior.

habit loop hooked model frameworks

Lesson 2: Triggering User Action

By understanding what internal or external triggers prompt users to use your product, you can design features that create triggers strategically throughout your product experience.

There are two types of triggers,

  • External triggers prompt users to initially engage with the product. I.e. What makes them want to interact with the product?
  • Internal triggers delve into users’ motivations and desires. These emotional or psychological cues drive users to seek out the product to fulfill a specific need or want. I.e. What does the user really want?

Let’s use TikTok as an example

Internal triggers, like boredom or curiosity, drive users’ actions. TikTok’s “For You” page acts as a magnet, drawing users in with personalized videos. As users open TikTok, their curiosity about new content keeps them scrolling.

This mix of internal triggers, such as curiosity, and external triggers, like fresh content, creates a potent combination. It’s this seamless blend of user-driven emotions and algorithmic recommendations that makes TikTok so addictive.

Applying this strategy

Understand what motivates your users behaviourally and psychologically and what triggers will prompt them to use your product. Then, prototype your “trigger features” by experimenting with different mechanisms to see which ones lead to the highest engagement.

For those who have already enrolled in RapidMVP, you can utilize my Prototype or Experiment Database to find inspiration for the types of experiments you can conduct and test with your users.

From: rapidmvps.com

Lesson 3: Simplify User Actions

Make actions as simple as possible for users to complete. By simplifying your product’s behavior to make it more predictable, you can increase the likelihood that users will take the actions you intend.

Here’s the thing: We all have short attention spans, and the more complicated the steps, the less motivated we are to stick around in an app.

That’s why actions, which are what users do in response to a trigger to get a reward, are designed to be easy and quick. This way, users can get what they need without any hassles. The key is to reduce friction in the user experience.

How to reduce friction:

  • Amazon’s “One-Click Ordering” and “Subscribe & Save.” These features allow users to make purchases with minimal effort and set up recurring orders for essential items.
  • Netflix’s “Continue Watching” and “Downloads” features let you easily pick up where you left off, with episodes downloading automatically for offline viewing, so you can binge-watch without interruption.
  • Airbnb simplifies booking with features like “Instant Book” and “Wishlist,” allowing users to book accommodations instantly and save favorite listings for future reference.

Applying this strategy

Map out the user’s stories and identify any potential barriers in completing actions. Then, see how many steps it takes to move from point A to point B. Work on reducing these steps. Keep refining the user journey to remove any unnecessary steps or complexities.

In RapidMVP, I provide a step-by-step video guidance on identifying obstacles your users face in their jobs-to-be-done. Here’s a sneak peek of the video course:

user stories mapping
From: rapidmvps.com

Lesson 4: Provide Variable Rewards

Offer users unpredictable and compelling rewards to keep them engaged.

Social media notifications provide a classic example of variable rewards. These platforms include built-in mechanisms such as likes, comments, shares, follows, or messages, which offer social validation as the reward.

Despite not knowing exactly when these notifications will appear, we keep checking our phones in anticipation of the next reward. This releases dopamine in your brain, which makes you feel good and reinforces the behavior of checking your phone.

The reason behind this behavior lies in a psychological concept known as “intermittent reinforcement.” Our brains are wired to respond strongly to unpredictable rewards. It’s similar to when you play a slot machine — you never know when or how much you’ll win, but the possibility keeps you coming back for more.

Let’s use Instagram as an example

  • Reels: offers users a diverse array of short, entertaining videos from various creators. The content is unpredictable and can range from funny clips to informative tutorials.
  • Feed Posts: Instagram’s feed is constantly updated with posts from accounts users follow, covering a wide range of interests.
  • Stories: This feature effectively provides a sense of urgency and FOMO (fear of missing out) because users know the content disappears after 24 hours. This makes users check back often to avoid missing updates from their favorite accounts, especially behind-the-scenes content from creators.

Applying this strategy

Make sure your product provides rewards that feel good and surprising, but also make sure they’re meaningful and important to users so they stay interested. Try out different types of content — experiment with different formats, when you show it, and how often, to keep users excited and wanting to come back. Add in fun features like progress bars, badges, or challenges to make using the app more like a game.

Lesson 5: User Investment

Prompt users to invest time, effort, data, or money into your product. Develop features that require users to invest in the platform, such as creating content, customizing settings, or building relationships.

Investment involves users putting in some effort or data to increase the likelihood of returning to the product.

Why does it work? Because it leverages the psychological attachment of the users. Psychological attachment can manifest in various forms.

For example

  • Emotional attachment: where users develop a bond with the product based on positive experiences or memories associated with it.
  • Identity attachment: where users integrate the product into their self-concept or personal identity.
  • Social attachment: where users feel connected to a community or network within the product. This sense of belonging encourages users to return to maintain their social connections and interactions.
  • Functional attachment: occurs when users rely on the product to fulfill specific needs or tasks. This reliance creates a habitual usage pattern, increasing the likelihood of users returning to the product.
product management tips

Ways to create user investment

  • Creating a profile: Invite users to provide information about themselves, like their interests, demographics, or preferences, fostering identity attachment.
  • Creating content: Encourage users to share posts, upload photos, leave a comment, or contribute reviews.
  • Customizing preferences: Provide options for users to personalize their experience by adjusting content settings or selecting preferences.
  • Learn advanced features. Show users the possibility of doing more with your platform. Implement engaging onboarding processes or step-by-step tutorials.
  • Tools or social integration. Allow users to integrate their data from other platforms or sync their social media accounts or contacts.

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Zoe Chew

Building things on the Internet at Venturescale.to & Rapidmvps.com. Here I share my learnings as an entrepreneur, writer and creator.