Designing to hook: applying the hooked model to product design

What is the Hooked Model? You may have yet to hear of it, or perhaps recall it being loosely referenced; that said, let’s dive in as it requires continued consideration and understanding. The model was created by Nir Eyal who was heavily focused on digital products when he defined this concept and subsequently wrote the book Hooked: How to Build Habit-Forming Products.

What the model aims to do is create a template for building product concepts which make the user want to repeatedly use said product; manufacturing desire in a way. What was once simply viewed as customer or brand loyalty, has now been reimagined for the age of digital products we live in today.

All this was previously handled through traditional marketing and advertising initiatives, with all the regular tactics therein; yet, now reinvented and applied in a very different way. Yet ultimately, the outcome is not all that dissimilar, but how you get there very much is. However, the danger with this model is that it more often than not creates addictive behaviours in users which is a genuine concern not to be dismissed or overlooked. Its application, either by accident or design, is the cause for many of the health and social issues society faces today as a consequence of the proliferation and dominance of social media.

The model consists of a four step process taking the form of a repeating loop for what will become obvious later. Let’s begin with a look at those four steps.

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The four phases

External trigger

So beginning with the first step, the external trigger. This one is the most well-known, and well explored for that matter, due to the fact that in many ways many of these external triggers are still fueled by good old-fashioned advertising. If you want people to know about and use your product, you need to get it in front of their face, grab their attention and entice them into the product.

There are a million and one different ways to advertise and they can all be useful in some way or another. Selecting which one will work best for your digital product is all you need to do, and ultimately you may need a few ways to be sure you cover your bases. The key point is the goal of the advertising; that is, it needs to bring users to your digital product. However, the best trigger will also inform the rest of the cycle by priming the user as to what they can expect, even linking eventual actions and rewards to potentially be had.


The next step kicks off with action; that is, everything the user can do on or with your software. Now the focus is certainly on the core actions executed within the application, yet I must point out that this step covers all actions, minor and major. For example, joining the app and looking at another user’s post, or a user joining and selecting their preferred account settings and so on. For a more in depth example, consider a user ordering a meal; something that requires them to perform a number of actions is series, each interconnecting and hooking them further into the app. For the model to be most effective, the core actions need to be focused on maintaining the hooked loop. In a way, the actions are an extension of the user developing a relationship with the app.

Therein you must be extremely meticulous with the design of how this functions so that each of these core actions informs a loop to keep the cycle going. There are a plethora of loops within the software that need user interaction in order to funnel the user to the next step of any given loop. The core actions need to be as seamless and simple as possible for the user to execute. Consequently, design and usability are paramount for this step to function correctly within the model.

Remember when it comes to design that pretty, flashy, wow and so on always work to grab the users attention and drive interaction with the software, but be careful to not go too far with this. Too far will lead you down the path of a cluttered user interface or confusing user experience that turns the tables on you and actually turns the users off.

Variable reward

Moving on to the third step, variable reward(s). We all like rewards and users love them so naturally the Hooked model must include them in order to capitalise on this most basic human instinct. This is where the Hooked loop differs from other feedback loops. Instead of just rewarding the user, the model designs rewards to create a sense of wonder, mystery and excitement for the user. The key point is variability as this creates an added layer of excitement to the rewards. People like rewards, and surprisingly enough, they like them even more when the reward is unknown. It may be expected, but when the user doesn’t know what the reward will be, they get a greater sense of excitement and therefore, the reward is able to more strongly hook them into the loop.

It’s similar to a dopamine rush or that of, you guessed it, gambling. Why do you think scratchcards are so popular? Ease of access, ease of play, low cost barrier, variable rewards… need I say more? Researchers have noted that dopamine is one of the key hormones for addiction so this is why leveraging this effect is an easy win for any type of product, including software. Slot machines are also a good example of the effectiveness of this variable reward. Mystery and surprise are two elements that are powerful when employed correctly as the child in everyone loves both mystery and surprise; the model looks to capitalise on all these elements within human nature.

To give an easy digital based example, consider the ever-rising tide of loot boxes in video games. The gamer completes a certain set of tasks or challenges, and in return is rewarded with a loot box. They don’t know what’s in the loot box until they open it, and every time, using Random Number Generation, the given rewards or items vary. You can even get two of the same item yet having different characteristics and therefore, usable in different cases or with different player characters, items etc, depending on the game. This excites the player and causes a dopamine rush upon opening the box, which subsequently pushes them to the final step of the loop.


Investment is the final step to hook the user into the loop and into your digital product. In this step the user needs to actually put a touch of effort into the product; it should be noted, this is the first real investment being directly asked of the user aside from the obvious time investment. “Why must the user invest?”, you may be wondering. Well, there are a number of reasons but mainly two I’d like to touch on here.

First reason is due to the fact they come into this step full of excitement, vigour and vim as it were. This means there is less perceived friction when being prompted to do something akin to work. This work could be something as simple as updating their preferences. These will allow the software to tailor itself to the individual user; therefore, deepening the hook loop and driving retention. The second reason being that it increases the odds the user will be ready for the next trigger which incidentally comes in the form of an internal trigger.

Internal trigger

Consider the internal trigger like an itch that just needs to be scratched. The user feels like they are missing something, or simply bored with the mundane of daily life. They crave for excitement and surprise, they think of their mobile game which provides loot boxes and bang, they’re picking up their phone to jump in the game and play for a bit to escape the mundane and be rewarded for their decision to do so. Hence, the design to hook the user is now complete.

As you are designing your product to hook the user into this cyclical loop, you can understand from the above phases how each one does so in a calculated manner all beginning with an external trigger. For any habit to continue, the trigger must be internalised for the habit to become innate. Now the loop is designed to plant seeds as it were into the user’s mind that act as internal triggers when the user is away from the product; just as with any habit.

Just as clever marketing for beverages looks to tap into one’s innate trigger to feel thirsty and therefore, buy something to drink; even when your body is not genuinely thirsty. Internal triggers can be finicky and a challenge to create, but when done right, the hook design is all that much more effective.

The real genius of the model is each loop’s inherent ability to build on itself, providing further triggers, actions and variable rewards that increase the overall investment as time goes on. This makes the user more and more “invested” into the loop, or rather product, as they have tied both behaviours to it as well as the time and effort. This links to the sunk-cost fallacy which is a phenomenon where any given user is hesitant to give up on something because they have heavily invested into it, even when it is clear that quitting would be more beneficial.
The more the user travels continually through the repeating loops, deeper down the rabbit hole, the more your product develops a deeper connection with the user’s daily life and routine. At this point, using your product becomes akin to a reflex action for the user; they are now hooked!

Much more can be said on the Hooked model as to its ethical implications as many rightfully argue it develops negative habits and can therefore, easily be exploited. Addiction is certainly no laughing matter and the model is not intended to prey upon users. That being said, all things can be used for good and bad, and in the world of product marketing, when results are key, there is a bit of an anything goes attitude. Everyone wants their product to be a success, otherwise why would they set out to create it in the first place. How you choose to design to hook is up to you. Using the model wisely will produce better long-term results than simply aiming to leverage the baser human instincts it can tap into if used poorly. Therefore, as with many addictive products nowadays, the following tagline seems apt: “Use responsibly!”

Byron Matthiopoulos
Byron Matthiopoulos
Managing Director
Byron Matthiopoulos joined as a Product Owner in 2018, shortly after moving to Cambodia, to help lead one of the biggest projects of the start-up at the time. His background as medical researcher, journalist & advertising photographer and diverse skills have provided a solid foundation for the complexities of the field of product building. His ability to assimilate multiple sources of data into a coherent vision allowed him to successfully run a number of exciting projects over the years. The diversity and complexity of his tasks since he joined Slash had perfectly positioned him to take over the role of Head of Product. He is now leading the ideation, design and creation of new and exciting products through user-centric digital innovation.
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