Here's a story about the tick that beat the giant with a trick
— Smith and Thell, Goliath

In January 2021, Signal was only known by journalists and privacy geeks. In a matter of days, it topped the charts and was on everyone's phones.

How did that happen?

TL;DR

Signal was an overnight success that was years in the making. The app had all the components that any alternative product needs to succeed:

1. Zero or low switching cost, which means:
   1. A seamless transition process
   2. Feature parity, almost
   3. Intuitive design
2. Issues with the status quo, i.e., a villain. The reason to switch has to be well-known and relatable.
3. Street credentials. If shouldn't be just you recommending the alternative.

What's the deal with WhatsApp and Signal?

WhatsApp, owned by Facebook/Meta is one of the main secure messaging apps. Signal is a similar app run by a non-profit with a small team. Interestingly, it was the Signal team that implemented WhatsApp's encryption.

These apps coeixsted for a while. WhatsApp was the mainstream app that almost everyone used, and Signal was the unknown that only journalists and privacy geeks used. Until everything changed.

One day, on January 2021 WhatsApp sent a notification to its users regarding a new privacy policy. The notification said that from 8th February, WhatsApp would start sharing data with its parent company (Facebook). The Internet started writing about the changes, and people started switching to Signal. A snowball effect ensued.

The overnight success

Signal became the most downloaded app in the App Store in India, Germany, France, Austria, Finland, Hong Kong, and Switzerland. The downloads went from 246,000 the week before the WhatsApp change to 8.8 million the week after. Facebook even bought ads for the word "signal" to prevent people from downloading it. 3 months after the initial incident, Facebook closed Signal's Instagram account.

This overnight success is attributed to Elon Musk advising people to "use Signal" on Twitter. While it made a gigantic difference, I don't think that's why it worked.

If Elon tweets "use Linux" tomorrow, no one will care. Why did "use Signal" work so well?

I. Zero or low switching cost

Convenience is everything.

1) A seamless transition process.

There are 4 steps to get on WhatsApp: Download the app, give it a phone number, wait for the text, and give it access to your contacts. That's it. For Signal, it's the exact same process. If Signal asked you to create an account, wait for a confirmation email, type a bio, enter a location, refer a friend, use a two-factor code, plus the other 4 steps, I wouldn't be writing this.

It should be as easy as possible to transition to the alternative. Otherwise people won't bother.

2) Feature parity, almost.

Open-source developers tend to pay too much attention to the specifics. In our case, Signal didn't have exactly the same features as WhatsApp. You couldn't search Emojis by their name, it didn't support group calls with more than 5 people, and the group admin features were limited. But it had most of the features that most people wanted.

It offered, all in all, a user experience that was similar enough.

Today, not only did Signal add all these missing features, it did so without sacrificing security and privacy. Continuing on my example with group calls, Signal now support group calls with up to 40 participants. That required a lot of engineering.

3) Intuitive design

The design of the the product must be pleasant, and easy to use. You should never have to learn a new app. Signal had a simple design without bells and whistles.

II. Issues with "the status quo"

Why would you switch when the current product works?

Claims like "It's Photoshop but open source" are terrible. They're appealing for developers but not the average person. "Photoshop without Adobe's pesky installer" is much better.

In Signal's case, Edward Snowden had recommended Signal for years. But humans are narrative creatures. We need a story to justify our behaviour. Issues have to be clear and resonate with people. It's not only chanting the merits of your alternative, it's about showing how ugly the status quo is.

WhatsApp was associated with security and privacy, but Facebook wasn't. That's what made people quit. The villain of the story became obvious.

III. Street credentials

The most discouraging problem with new social apps is "nobody I know uses that." This creates a self-defeating downward spiral that keeps the user base low.

Signal had just enough notoriety that it wasn't completely unknown. After Elon Musk's tweet, other celebrities joined the fun. Signal's founder and CEO was invited on The Joe Rogan Experiment, one of the biggest podcasts in the world.

As a result of that, Signal became a known quantity. When people asked their friends and families about this "signal thing," someone had heard of it somewhere.

What now?

There were multiple factors that contributed towards Signal's success. But the main takeaway is this: Make a great alternative product, and don't compromise.

If you're an early user of giving feedback about a new app, demand no less than a great UX. Don't worry about the small stuff. Don't nitpick about a feature if most people don't need it.

If you're a creator/developer, nail the core product, then reach out. I'm as jaded of the marketing logo wall as everyone else, but the beginnings are always tough. I get it, it's easy to forget UX glitches when you're too close to the product. And it's much more fun to work on a coding problem than crafting a compelling marketing message.

My hope is to see this success is replicated. More competition is better for consumers, well, most of the time. Remember when there was only one TV subscription service?

Thank you to Jeremiah Lee and Kev Quirk for reviewing drafts of this article.