Book notes: Hooked

I recently had the chance to read through this book: Hooked: How to Build Habit-Forming Products. It is my attempt at bringing back the “builder” spirit. I have worked on side projects that are literally whatever I like to do with my time at any given point - LOL :D

So, I thought I will learn how some good products are getting built. Apart from that, this book is about “habit-forming products”. By this time, I have realized that I have a “habit” of using certain things every day - I don’t even know how it became a habit, but it is a habit for me now (example: picking up the phone to check Twitter). So, I was curious to understand how I ended up like this and probably use the book in reverse-effect to control my habits (so that they don’t become an addiction).

Overall, I liked the book and I am going to have a “worksheet” of things discussed in the book before I start building anything new. So, I am writing this blog post to revise the notes when it is needed. The entire post is mostly my “notes and highlights” from the book.

As one of its findings, the study concluded that the more frequently the new behavior occurred, the stronger the habit became.

So Why haven’t more Google users switched to Bing? Habits keep users loyal

Sometimes a behavior does not occur as frequently as flossing or Googling, but it still becomes a habit. For an infrequent action to become a habit, the user must perceive a high degree of utility either from gaining pleasure or avoiding pain

A company can begin to determine its product’s habit-forming potential by plotting two factors: frequency (how often the behavior occurs) and perceived utility (how useful and rewarding the behavior is in the user’s mind over alternative solutions)

Just as failure has many causes, success too can be attributed to a variety of factors. However. one aspect is common to all successful innovations - they solve problems.

“Are you building a vitamin or painkiller?” is a common, almost clichéd question many investors ask founders eager to cash their first venture capital check.

A habit is when not doing an action causes a bit of discomfort

The book introduces four parameters that we should think about while building new products. They are

  • Trigger
  • Action
  • Variable Reward
  • Investment


A trigger is something that triggers the user to use your product. There are two kinds of triggers: External and Internal triggers.

External triggers:

  • Paid Triggers: Advertising, search engine marketing, etc.
  • Earned Triggers: Favourable Press mentions, features on the app store, etc.
  • Relationship Triggers: Word of mouth, referrals, somebody shared on social media, etc.
  • Owned Triggers: Email newsletter to which user is subscribed, app icon on user’s iPhone screen, bookmarks, app notifications, etc.

Internal triggers:
You can’t see, touch, or hear an internal trigger. It is completely internal to the user. They probably are triggered due to the feelings/emotions/state of mind of the user.

When do you use Instagram? FOMO - Fear Of Missing Out updates from your friends (fear is the emotion)

Emotions, particularly negative ones, are powerful internal triggers and greatly influence our daily routines.

Our life is filled with tiny stressors and we’re usually unaware of our habitual reactions to these nagging issues.

The study demonstrated that people suffering from symptoms of depression used the Internet more. Why is that? One hypothesis is that those with depression experience negative emotions more frequently than the general population and seek relief by turning to technology to life their mood.

Jack Dorsey, co-founder of Twitter and Square, shared how his companies answer these important questions: “[If] you want to build a product that is relevant to folks, you need to put yourself in their shoes and you need to write a story from their side. So, we spend a lot of time writing what’s called user narratives.

Dorsey goes on to describe how he tried to truly understand his user: “He is in the middle of Chicago and they go to a coffee store … This is the experience they’re going to have. It reads like a play. It’s really, really beautiful. If you do that story well, then all of the prioritization, all of the product, all of the design, and all the coordination that you need to do with these products just falls out naturally because you can edit the story and everyone can relate to the story from all levels of an organization, engineers to operation to support to designers to the business side of the house.”

One method is to try asking the question “Why? as many times as it takes to get to emotion. Usually, this will happen by the fifth why. This is a technique adapted from Toyota Production System, described by Taiichi Ohno as the “5 Whys Method.” Ohno wrote that it was “the basis of Toyota’s scientific approach… by repeating ‘why?’ fives times, the nature of the problem, as well as its solution, becomes clear”


Fogg posits that there are three ingredients required to initiate any and all behaviors: (1) the user must have sufficient motivation; (2) the user must have the ability to complete the desired action; and (3) a trigger must be present to activate the behavior.

The Fogg Behaviour Model is represented in the formula B = MAT, which represents that a given behavior will occur when motivation, ability, and a trigger are present at the same time and insufficient degrees.

Evan Williams, co-founder of Blogger, Twitter, and Medium, echoes Hauptly’s formula for innovation when he describes his own approach to building three massively successful companies:

“Take a human desire, preferably one that has been around for a really long time… Identify that desire and use modern technology to take out steps.”

The book introduces something called “Fogg’s elements of simplicity”. These are the factors that influence a task’s difficulty. They are

  • Time - how long it takes to complete an action.
  • Money - the fiscal cost of taking an action.
  • Physical effort - the amount of labor involved in taking the action.
  • Brain cycles - the level of mental effort and the focus required to take an action.
  • Social deviance - how accepted the behavior is by others
  • Non-routine - according to Fogg, “How much the action matches or disrupts existing routines”

To increase the likelihood that a behavior will occur, Fogg instructs designers to focus on simplicity as a function of the user’s scarcest resource at that moment. In other words: Identify what the user is missing. What is making it difficult for the user to accomplish the desired action?

Is the user short on time? Is the behavior too expensive? Is the user exhausted after a long day of work? Is the product too difficult to understand? Is the user in a social context where the behavior could be perceived as inappropriate? Is the behavior simply so far removed from the user’s normal routine that its strangeness is off-putting?

These factors will differ by person and context: therefore, designers should ask, “What is the thing that is missing that would allow my users to proceed to the next step?” Designing with an eye toward simplifying the overall user experience reduces friction, removes obstacles, and helps push the user across Fogg’s action line.

I have come across various brain “biases”. I felt it to be mostly psychological theory. But the book picked up four biases in particular and tries to explain with help of examples. (Found it to be practical)

  • The Scarcity Effect - This is why Amazon shows “1 out of 10 remaining in stock”
  • The Framing Effect - This is why you should care about the design of the box you package your product with.
  • The Anchoring Effect - “Buy one, get two”, “Shops that have 20% off always”
  • The Endowed Progress Effect - This is why most sign-up flows show progress (Like Linkedin showing 80% complete to making you fill to becomes an “All-star” profile”)

The appearance of scarcity affected their perception of value.

People often anchor to one piece of information when making a decision.

The study demonstrates the endowed progress effect, a phenomenon that increases motivation as people believe they are nearing a goal.

Variable Reward

Reward your users by solving a problem, reinforcing their motivation for the action taken in the previous phase.

I think variable rewards pay for internal triggers. This section like many sections in the book is filled with research data and past experiments.

The variable reward comes in three types:

  • Rewards of the Tribe: Facebook Likes and comments.Stack overflow upvotes of answers.
  • Rewards of the Hunt: Twitter’s feed and Pinterest’s endless scroll.
  • Rewards of the Self: Video games, Codecademy’s progress bar on skill development.

The magic words the researchers discovered? The phrase “But you are free to accept or refuse”

The “but you are free” technique demonstrates how we are more likely to be persuaded to give when our ability to choose is reaffirmed. Not only was the effect observed during face-to-face interactions, but also over email. Although the research did not directly look at how products and services might use the technique, the study provides an important insight into how companies maintain or lose the user’s attention.”


Unlike its competitors who sell preassembled merchandise, IKEA puts its customers to work. It turns out there’s a hidden benefit to making users invest physical effort in assembling the product - by asking customers to assemble their own furniture, Ariely believes they adopt an irrational love of the furniture they built, just like the test subjects did in the origami experiments. Business that leverage user effort confers higher value to their products simply because their users have put work into them. The users have invested in the products through their labor.

Studies reveal that our past is an excellent predictor of our future.

The product has to provide “value” to keep the user invested in the product. Some ways of providing value:

  • Content: Spotify’s users consume the content it provides. Spotify generates “Discover Weekly” based on content consumption which provides more value to the user who invested in listening on Spotify.
  • Data: stores all the financial data of a user.
  • Followers: Investing in following the right people on Twitter improves the service for the user.
  • Reputation: Online marketplaces such as eBay, Upwork, Yelp, and Airbnb, people with negative scores are treated very differently from those with good reputations.
  • Skill: Investing time and effort into learning to use a product is a form of investment and stored value. Example: Learning Adobe Photoshop is an investment that adds design skills to the users as a result of which they are more invested in the product.

Habit Testing

For example, in its early days, Twitter discovered that once new users followed thirty other members, they hit a tipping point that dramatically increased the odds they would keep using the site.

Twitter used the insights gained from the previous step to modify its onboarding process, encouraging new users to immediately begin following others.


Throughout the book, I felt that the author applied the principles to the book itself. One thing that put a smile on my face was during the closing chapter of the book, the authors say this

Also, it would mean so much to me if you could take a moment to review the book online, “but you are free to accept or refuse”