Nir Eyal - Hooked: how to build habit-forming products


I've just attended Nir Eyal's excellent talk on habit-forming products, and thought I'd summarize it before buying his book.


Many highly successful companies started out as toys: Lego, Facebook, Twitter, Instagram, Snapchat. Are these companies

  • "vitamins", improving your life by a little bit, and not always for sure; nice-to-haves
  • "pain-killers", clearly fixing a problem customers have

The answer is they started as vitamins, and became painkillers because they have created a habit. Today, many of us can't wait to check their Facebook or email when they wake up. That, is a habit - a behavior done with little conscious thought. Withdrawing Facebook or your favorite chat app would create emotional pain.

A habit is when not performing a behavior causes pain

Products attempt to form positive habits, not addictions: LUMO (posture), (learning about people you're meeting), Fitocracy (fitness-centered social network).

How to form habits

Two things matter most:

  1. Frequency: at least weekly, or else the behavior is likely to die. No definite studies on minimum frequency.
  2. Attitude change. E.g. Twitter, from "silly" in 2009 to enabling social change.

Creating habits is very valuable for your business, but is hard work and exceptionally rare - we've adopted maybe 5 or 10 products for habitual use over the past 10 years.

The Hook Model

A hook has 4 parts

Habits aren't built, but formed around other habits.

A hook has 4 parts: trigger, action, reward, investment.


  • external - the information about what to do next is in the trigger itself. Examples: "Buy now!", billboards, app icons, new notification counts, emails
  • internal - the information is in the user's mind: places, people, routines, situations. Negative emotions are POWERFUL INTERNAL TRIGGERS: lonesome, indecisive, powerless, tense, dissatisfied, confused, inferior, fatigued, discouraged, fear of missing out (FOMO - a pretty legit word), bored

Do you know your customers' internal triggers?

Instagram example triggers:

  • external:
    1. find out about it from other people's Facebook posts, Tweets etc.
    2. install app => app icon on phone
    3. app notifications
  • internal: solves the pain of losing the moment


What is the simplest thing the user can do in anticipation of the reward?

  • scrolling on Pinterest
  • searching on Google
  • clicking Play on YouTube

According to Stanford behavioral psychologist BJ Fogg, for any behavior to occur, we need motivation, ability, and a trigger.

Motivation is increased by six factors

  • seeking pleasure / avoiding pain
  • seeking hope / avoiding fear
  • seeking acceptance / avoiding rejection

Ability is the capacity to perform an action

Ability is affected by:

  • time
  • money
  • physical effort required
  • mental effort required - simple is better
  • social conformity vs. deviance - do others do it?
  • routine - the more we do it, the easier it is

When behavior happens

When triggers succeed

A great example of a business optimizing for the behavior to happen is Twitter's homepage:

  • the 2009 version (a bunch of text describing what twitter is, plus links for "How", "Why" etc. - these are all triggers, and too many of them)
  • the 2013 version: the only things you can do are to either sign in or sign up. The decision is much simpler, and the text describing what Twitter is was removed because nobody arrives at by mistake - people already know what it is by the time they land on the home page.

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Driven by the nucleus accumbens - an area in the brain that is involved in reinforcement learning and is activated when we crave. Studies have shown that rats and humans will go to great lengths to pleasure that center (forgo food, undergo electric shocks etc.)

The NAcc creates that "itch" that we need to scratch. And here's how to activate it...

Our reward system activates with anticipation, and calms down when we get what we want

So here's how to supercharge it:

THE UNKNOWN is fascinating. Variability causes engagement

Variability and random reinforcement (intermittent rewards - see my Toastmasters talk on Random Reinforcement) supercharge the NAcc.

There are three types of rewards:

  1. Tribe - social rewards: partnership, cooperation, empathetic joy, recognition
  2. Hunt - acquiring resources:
    • material: the great clothing item at a clearance sale, the slot machine cash
    • informational: the interesting status update, the fun tweet
  3. Self - intrinsic motivators. Games are great at it (e.g. upgrade your character - mastery and competency). Task management systems reward consistency and completion (e.g. zero unread emails in your inbox)


  • The hunt is rewarding for the nuggets of good stuff.
  • Gratuitous gamification doesn't work. The variable rewards must be meaningful, and must make the user want more.


Users "invest" for future benefit:

  • time
  • effort
  • money
  • personal data
  • emotional commitment
  • social capital (e.g. asking friends to join)

Investment makes it likelier for the hook loop to repeat:

  1. loads the next trigger - when you send a message, there's no immediate rewards - but you do expect a reply! On Pinterest, repinning, following, commenting pave the way for replies and notifications - more triggers.
  2. creates value - content, reputation. When would you pay for Twitter to stay in business if they asked - when you have 20 followers, or when you have 10,000?

Unlike physical products, the value of digital products increases with use

Investments create preference, thanks to our innate tendency to preserve consistency and avoid cognitive dissonance (the fox and the grapes fable).

Summary / Takeaway

Ask yourself these questions regarding your product:

The Hook Canvas

Technology is, quite possibly, the cigarette of the century.


How to hook users of infrequently use products:

  • Make the experience salient or memorable. Consider that you only need to get burned by a stove once, to never touch one again.
  • Require a very high investment. TurboTax is a great example - users spend many hours with the product once a year, and would not want to learn a new one.

Health apps fail to hook users because of reactance - a a motivational reaction to offers, persons, or rules that threaten or eliminate specific behavioral freedoms. Occurs when a person feels that someone or something is taking away his or her choices or limiting the range of alternatives. Effect: opposition to the offer. Fitocracy is one of the few fitness apps that instead of nagging users with reminders of being unfit, matches them up with others who enjoy the same sport activity.

Track user activity and see what the most active 5% do. Then optimize your UX flow so that all users are exposed to those triggers. Twitter did this in the beginning and noticed that the top 5% active users had followed at least 10 other users in the first minutes after signing up. Now, when you sign up with Twitter, you'll be following a bunch of users right away.

How to create network effects and a critical mass:

  1. seed the market - Facebook started with a few college campuses
  2. make the product useful in standalone mode - Pinterest approaches interior designers at conferences and proposed the service as an alternative to ripping off pictures from Architectural Digest and storing them in folders


Hooked Model from Nir Eyal

More info

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