Nir Eyal: What Makes Some Products Indispensable?

Written

Nir Eyal: What Makes Some Products Indispensable?

A writer and lecturer explains how one of the most popular Bible apps in the world is engineered to be habit-forming.
Illustration of hands holding a smart phone by Anna Parini.

It's not often an app has the power to help keep someone out of a strip club. But according to Bobby Gruenewald, CEO of YouVersion, that's exactly what his technology did: A user of his Bible verse app walked into a business of ill repute when suddenly, seemingly out of the heavens, he received a notification on his phone with a custom-selected verse from the Bible. "God's trying to tell me something," the user thought, according to Gruenewald.

By July 2013, that app, simply called Bible, had been downloaded to more than 100 million devices, a monumental milestone that places it in a rare stratum of apps, including Instagram, which reached it in February 2013.

Gruenewald says that today his app is on more than 138 million devices. A new install occurs every 1.3 seconds, making it by far the most popular of the 5,000-plus Bible apps now available in Apple's App Store. What's more, YouVersion's Bible boasts more than 690,000 reviews, and an average of 475,200 people open the app every hour; sometimes the open rate is much higher. Every Sunday, Gruenewald says, preachers around the world tell congregants to "'take out your Bibles or YouVersion app,' and we see a huge spike."

How did YouVersion come to dominate the digital "Word of God"? It turns out there is much more behind the app's success than religious zeal. It's a case study in how designers use technology to create habit-forming products by marrying the principles of consumer psychology with the latest in big data analytics. Indeed, it is just one of many products and services we use habitually that alter our everyday behavior — just as their designers intended.

How does it work? After years of distilled research and real-world experience, I call it the Hook Model: a four-phase process companies use to form habits. Through consecutive hook cycles — of trigger, action, variable reward, and investment — successful products reach their ultimate goal of unprompted user engagement, bringing users back repeatedly without depending on costly advertising or aggressive messaging. To illustrate this, it's helpful to look at the early days of Gruenewald's Bible app.

In the Beginning

Gruenewald is a quick-thinking, fast-talking man who pulls up statistics in real time and stops himself midsentence whenever relevant data flashes on his screen.

"Unlike other companies, when we started, we were not building a Bible reader for seminary students. YouVersion was designed to be used by everyone, every day," Gruenewald says, attributing much of the app's success to a relentless focus on creating habitual Bible readers. "We originally started as a desktop website, but that really didn't engage people in the Bible. It wasn't until we tried a mobile version that we noticed a difference in people, including ourselves, turning to the Bible more because it was on a device they always had with them."

This is not surprising. While there are many theories about what drives human behaviors, B.J. Fogg, Director of the Persuasive Technology Lab at Stanford University, has developed a model that serves as a relatively simple way to understand what drives our actions. The Fogg Behavior Model posits that there are three ingredients required to initiate any behavior: the user must have (1) sufficient motivation, (2) the ability to complete the desired action, and (3) a trigger to activate the behavior. If any element is missing or inadequate, the user will not cross the "Action Line" and the behavior will not occur.

The omnipresence of the Bible app makes it far more accessible than its website predecessor, giving users the ability to open the mobile app when triggered by the pastor's instructions or when feeling inspired at other moments throughout their day. Its users take it everywhere, reading the scripture in even the most unsanctified places: The company revealed that 18 percent of readers report using the Bible app in the bathroom.

How to Form a God Habit

To take advantage of the newly established App Store, in 2008, Gruenewald quickly converted his website into a mobile app optimized for reading. The app caught the rising tide, but soon a wave of competition followed. If his app was to reign supreme, Gruenewald needed to hook users quickly.

That's when Gruenewald implemented a plan — actually, many plans. A signature of the Bible app is its selection of over 400 reading plans — a devotional iTunes of sorts, catering to an audience with diverse tastes, troubles, and tongues.

Given my personal interest and research into habit-forming technology, I decide to start a Bible reading plan of my own. A plan titled "Addictions" seems appropriate.

For those who have yet to form a routine around Biblical study, reading plans provide structure and guidance. "Certain sections of the Bible can be difficult for people to get through," Gruenewald says. "By offering reading plans with different small sections of the Bible each day, it helps keep [readers] from giving up."

By parsing readings into digestible portions, the app focuses the reader's brain on the small task at hand while avoiding the intimidation of reading the entire book.

Six years of testing and tinkering have helped Gruenewald's team discover what works best. To get users to open the app every day, the app sends effective cues — like the notification sent to the sinner in the strip club. But Gruenewald admits he stumbled upon the power of good triggers. "At first we were very worried about sending people notifications. We didn't want to bother them too much."

To test how much contact users were willing to bear, Gruenewald decided to run an experiment: At Christmas, the app sent users a simple message, 'Merry Christmas' in various languages. The team braced itself to hear from disgruntled users annoyed by the message. "We were afraid people would uninstall the app," Gruenewald says. "But just the opposite happened. People took pictures of the notification on their phones and started sharing them on Instagram, Twitter, and Facebook. They felt God was reaching out to them."

Today, Gruenewald says, triggers play an important role in every reading plan.

On my own plan, I receive a daily notification — an external trigger — on my phone that simply says, "Don't forget to read your Addictions reading plan." (Ironically, the addiction I'm trying to cure is my dependency on digital gadgetry, but what the hell, I'll fall off the wagon just this once.)

In case I somehow avoid the first message, a red badge over a tiny Holy Bible icon on my phone cues me again. If I forget to start the first day of a plan, I'll receive a message suggesting that perhaps I should try a different, less-challenging plan. I also have the option of receiving verse through email. And if I slip up and miss a few days, another email reminds me to get back on track.

The Bible app also comes with a virtual congregation of sorts. Members tend to send encouraging words to one another, delivering even more triggers to open the app. These relationship-based external triggers are everywhere in the Bible app and are one of the keys to keeping users engaged.

Glory Be in the Data

Gruenewald's team sifts through behavioral data collected from millions of readers to better understand what users want from the app and what drives user retention. High on the list of learnings is the importance of ease of use, which came up throughout our conversation.

In line with the work of psychologists ranging from early Gestalt psychologist Kurt Lewin to modern-day researchers, the app uses the principle that by making an intended action easier to do, people will do it more often. For example, users who prefer listening over reading can simply tap a small icon to play an audio track read with the dramatic bravado of Charlton Heston himself.

Gruenewald says data also revealed that changing the order of the Bible by placing the more interesting sections up-front and saving the boring bits for later increased completion rates. Furthermore, daily reading plans are kept to a simple inspirational thought and a few short verses for newcomers. The idea is to get neophytes to devote a few minutes each day until the ritual becomes a facet of their everyday lives.

Gruenewald says the connection people have with scripture taps into deep emotions that "we need to use responsibly." Readers who form a habit of using the app turn to it not only when they see a notification on their phone, but also whenever they feel low and need a way to lift their spirits.

"We believe that the Bible is a way God speaks to us," Gruenewald says. "When people see a verse, they see wisdom or truth they can apply to their lives or a situation they're going through." Skeptics might call this subjective validation, but to the faithful, it amounts to personal communication with God.

Upon opening the Bible app, I find a specially selected verse waiting for me on the topic of "Addictions." With just two taps I'm reading 1 Thessalonians 5:11 — encouragement for the "children of the day," imploring them, "let us be sober." It's easy to see how these comforting words could serve as a sort of prize wrapped inside the app, helping readers feel better.

The Bible app also offers an element of suspense with its variability. "One woman would stay up until just past midnight to know what verse she had received for her next day," Gruenewald says. The unknown — in this case, which verse will be chosen for the reader and how it relates to his or her personal struggle — becomes a variable reward and an important driver of the reading habit.

Another reward, I discover, is a satisfying "Day Complete!" screen that appears after I finish my verse. A check mark appears near the scripture I have read and another one is placed on my reading plan calendar. Skipping a day would mean breaking the chain of checked days, employing what psychologists call the "endowed progress effect" — a tactic also used by video game designers to encourage progression.

As habit-forming as the Bible app's reading plans may be, they are not for everyone. In fact, Gruenewald reports most users download the app but never register for an account with YouVersion. Millions choose to not follow any plan, opting instead to use the app as a substitute for their paper Bibles. But to Gruenewald, using the app in this way suits him fine. Unregistered readers are still helping to grow the app via social media sharing.

To help the app spread, a new verse greets the reader on the first page. Below the verse, a large blue button reads, "Share Verse of the Day." One click and the daily scripture blasted to Facebook or Twitter. It works: Social media is abuzz with more than 200,000 pieces of content shared from the app every 24 hours.

The drivers behind sharing recently read scripture have not been widely studied. However, one reason may be the reward of portraying oneself in a positive light, also known as the "humblebrag." A 2012 Harvard meta-analysis entitled "Disclosing information about the self is intrinsically rewarding" found that disclosure "engages neural and cognitive mechanisms associated with reward," and that, in one study, "individuals were willing to forgo money to disclose about the self."

Devotion Runs Deep

Nothing signals the reign of Gruenewald's Bible app quite like the way some preachers have come to depend upon it. YouVersion lets religious leaders input their sermons into the app so their congregants can follow along in real-time — book, verse, and passage — all without flipping a page. Once the head of the church is hooked, the congregation is sure to follow.

Using the Bible app at church not only has the benefit of driving growth, it also builds commitment. Every time users highlight a verse, add a comment, create a bookmark, or share from the app, they invest in it.

Noted behavioral economist Dan Ariely calls this the "IKEA effect." His research shows that investing even a small amount of labor in something increases that item's perceived worth.

It is reasonable to think that the more readers put into the Bible app in the form of small investments, the more it becomes a repository of their history of worship. Like a dog-eared book, full of scribbled insights and wisdom, the app becomes a treasured asset that won't easily be discarded. Switching to a different digital Bible becomes less likely with each new revelation users type into (or extract from) the app, further securing YouVersion's dominion.

Gruenewald claims he is not in competition with anyone, but he does plan to continue sifting through the terabytes of data in search of new ways to increase the reach of his app and make his version of the Bible even more habit-forming, to which his ever-growing base of tens of millions of regular users say, "Amen."

Excerpted from Hooked: How to Build Habit-Forming Products by Nir Eyal with Ryan Hoover. Copyright 2014. All rights reserved. Nir Eyal received his MBA from Stanford GSB in 2008, and blogs about technology and behavior at nirandfar.com.

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