In 2011, indie game studio Tiny Speck launched Glitch, an anti-combat MMO which failed to gain any interest. Due to the team being located in three locations, it built an instant-messenger during development to better communicate online, which became a hub of activity.
Seeing the opportunity, co-founder and CEO Stewart Butterfield shut down Glitch in 2012 and began to work full-time on the messaging app, which would become Slack.
This was Butterfield’s second time pivoting a failed game project into a successful tech product. In 2002, his video game studio Ludicorp started work on Game Neverending, which never made it to launch. Some of the game’s features were used to create Flickr, which he sold to Yahoo in 2004 for $25 million.
It is worth noting the similarities between Slack’s founding and Discord. Both were run by entrepreneurs who had made millions from their previous venture (Flickr and OpenFeint) and then released a video game to muted reception. That failure inspired both to launch communication tools.
Originally beta testing the app with a few organisations, Butterfield saw the potential of Slack as an answer to the many disparate ways employees communicated. Instead of meetings, e-mail threads and phone calls, everything could be done through one application.
According to Slack, using the app reduces emails by 32 percent and meetings by 27 percent.
After a year of privately testing the app, Slack launched publicly in February 2014. It was an instant success, receiving 8,000 requests in the first day and 15,000 by the second week. Slack had to stagger the launch, as it added more server capacity to meet demand.
As Slack added more organisations, word of mouth accelerated demand, as many media organisations were the first to use the app and wrote positive reviews of it. It grew at a rate of five to 10 percent a week in the first year. Slack reached unicorn startup status in 2014, and its value almost trebled the next year when it was valued at $2.8 billion.
Slack’s first few years were led by the app’s user experience, which was easier and modern compared to Hipchat or Campfire, the two other notable online chat tools used at the time. In 2016, Slack debuted a flurry of new features to push it beyond the competition, including an app and bot ecosystem.
The use of bots made it easier for managers to relocate most of their operations to Slack. Managers could track employee time off, send surveys, receive and forward emails, and talk to clients through the app.
Business tools, such as Google Drive, GitHub, Asana, Zapier and Salesforce, are all integrated into Slack as well. Some have built an app inside Slack, allowing users to stay on the platform, while others simply inform users of any changes or updates to files. There are over 2,000 apps and 750 bots on the Slack App Directory.
For the past three years, Slack and Microsoft have gone back and forth at each other, with most of the barbs coming from Slack. Butterfield has said Microsoft is “unhealthily preoccupied with killing [Slack]” and recently filed an anti-trust lawsuit, due to Microsoft use of the Office 365 platform to accelerate Teams adoption.
While Slack has grown steadily in daily active users (DAUs), from six million when Teams launched to 12 million in 2020, Microsoft Teams has surged ahead, currently at 75 million DAUs. This is partly due to Microsoft marketing Teams as a catch-all solution for people and organisations affected by COVID-19.
Butterfield has also accused Microsoft of “fudging the numbers” by saying a Teams user is active simply for having the app open or using it for less than 10 minutes per day. Microsoft has refuted those claims.
Microsoft appears set on making Teams the communications platform for everyone, but that doesn’t necessarily mean Slack will be crushed. As Butterfield said in 2019, 70 percent of the company’s top 50 biggest customers use Office 365 in tandem with Slack.
It has taken some of the shine from Slack however, which was the darling of the tech industry. From a high of $23 billion post-IPO, Slack’s value dropped to $17 billion. Salesforce announced its intention to acquire Slack for $27.7 billion on December 1, 2020.
We have collected data and statistics on Slack. Read on below to find out more.
Slack key statistics
- Slack generated $902 million revenue between March 2020 to April 2021, a 43% increase year-on-year
- Net loss also decreased from $567 million to $292 million in that same period
- Slack has 18 million daily active users and 156,000 organisations use the app
- In December 2020, Slack was acquired by Salesforce for $27.7 billion
Slack overview
| Title | Title 2 |
|---|---|
| Launch date | 14 August 2013 |
| HQ | San Francisco, California |
| People | Stewart Butterfield (co-founder, CEO), Cal Henderson (co-founder, CTO) |
| Business type | Subsidiary |
| Owner | Salesforce |
| Industry | Business communication |
Slack revenue
Slack made $902 million revenue in 2021. Salesforce forecast revenue to be $1.5 billion for the next year.
Slack annual revenue 2014 to 2021 ($mm)
| Year | Revenue ($mm) |
|---|---|
| 2014 | 12 |
| 2015 | 30 |
| 2016 | 100 |
| 2017 | 200 |
| 2018 | 221 |
| 2019 | 401 |
| 2020 | 630 |
| 2021 | 902 |
Note: Slack’s fiscal year runs from March to April. Sources: Business Insider, Company data
Slack profit
Slack has not had a profitable year since launch, but net losses lowered in 2021 to $292 million.
Slack annual net income/loss 2017 to 2021 ($mm)
| Year | Net income/loss ($mm) |
|---|---|
| 2017 | -146 |
| 2018 | -140 |
| 2019 | -138 |
| 2020 | -567 |
| 2021 | -292 |
Sources: Company data, VentureBeat
Slack users
Slack had an estimated 18 million active users in 2020. We expect that has surpassed 20 million since.
Slack annual users 2015 to 202o (mm)
| Year | Users (mm) |
|---|---|
| 2015 | 2 |
| 2016 | 4 |
| 2017 | 6 |
| 2018 | 8 |
| 2019 | 12 |
| 2020 | 18 |
Note: 2020 values are estimated. Sources: Company data, Fast Company, The Verge
Slack paying customers
Slack had 156,000 paying customers in 2021, most of them organisations that actively use the platform.
Slack annual paying customers 2017 to 2021
| Year | Paying customers |
|---|---|
| 2017 | 50,000 |
| 2018 | 60,000 |
| 2019 | 88,000 |
| 2020 | 112,000 |
| 2021 | 156,000 |
Source: Company data
Slack organisations
There were 750,000 organisations using Slack in 2020, although the majority of them don’t pay for the service.
Slack annual organisations using app 2014 to 202o
| Year | Organisations |
|---|---|
| 2014 | 30,000 |
| 2015 | 60,000 |
| 2016 | 200,000 |
| 2017 | 330,000 |
| 2018 | 450,000 |
| 2019 | 640,000 |
| 2020 | 750,000 |
Note: Many organisations do not pay for Slack. Sources: Company data, Fast Company, The Verge
Slack valuation
Slack’s public valuation peaked in 2019 at $23 billion. Salesforce purchase was $10 billion higher than its market cap at the time.
Slack valuation 2014 to 2021 ($bn)
| Year | Valuation ($bn) |
|---|---|
| 2014 | 1.1 |
| 2015 | 2.8 |
| 2016 | 3.8 |
| 2017 | 5 |
| 2018 | 7.1 |
| 2019 | 23 |
| 2020 | 17 |
| 2021 | 27 |
Sources: VentureBeat, TechCrunch, FT
Slack vs Microsoft Teams: DAUs and Organisations
Slack FAQ
How many Fortune 100 companies use Slack?
According to Slack, 65 of the Fortune 100 use Slack in some capacity
Which are some of the largest organisations using Slack
IBM, Amazon, PayPal and Airbnb all use Slack
How active is the average Slack user?
Users are active for 90 minutes per day on weekdays, according to Slack in 2019
How much does Slack reduce email?
According to Slack, using the app reduces emails by 32 percent and meetings by 27 percent
How many messages are sent on Slack per week?
1.5 billion messages are sent on the service every week
How many developers are registered on Slack?
Over 500,000 developers use Slack
How many apps are built for Slack
There are 2,000 apps and 750 bots available in the Slack App Directory
