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.
Starting in 2018, Microsoft and Slack competed heavily for business customers, with Microsoft trying hard to push teams as the communication app for businesses. This led to an anti-trust lawsuit filed by Slack, and several barbs thrown back and forth by then Slack CEO Stewart Butterfield and Microsoft CEO Satya Nadella. Microsoft grew Teams at a far faster speed than Slack could, although Butterfield has on several occasions accused Microsoft of fudging its numbers.
After a few years on the public market, Salesforce acquired Slack for $27.7 billion in July 2021, integrating it into the company’s enterprise services portfolio.
We have collected data and statistics on Slack. Read on below to find out more.
Slack Key Statistics
- Slack generated $1.7 billion revenue in 2023, according to Salesforce’s full year financials
- Slack had an estimated 42 million daily active users on its app in 2023
- Over one million organisations use Slack as their communication platform
- 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 | Marc Benioff (CEO, Salesforce), Denise Dresser (CEO, Slack) |
| Business type | Subsidiary |
| Owner | Salesforce |
| Industry | Business communication |
Slack Revenue
Slack made $1.7 billion revenue in 2023, a 17% increase on the year prior.
Slack revenue 2014 to 2023 ($mm)
| Year | Revenue ($mm) |
|---|---|
| 2014 | 12 |
| 2015 | 30 |
| 2016 | 100 |
| 2017 | 200 |
| 2018 | 221 |
| 2019 | 401 |
| 2020 | 630 |
| 2021 | 902 |
| 2022 | 1500 |
| 2023 | 1755 |
Sources: Business Insider, Company data
Slack Users
Slack had an estimated 42 million active users in 2024.
Slack users 2015 to 2024 (mm)
| Year | Users (mm) |
|---|---|
| 2015 | 2 |
| 2016 | 4 |
| 2017 | 6 |
| 2018 | 8 |
| 2019 | 12 |
| 2020 | 18 |
| 2021 | 25 |
| 2022 | 35 |
| 2023 | 38 |
| 2024 | 42 |
Sources: Company data, Fast Company, The Verge
Slack Organisations
There were over one million organisations using Slack in 2023.
Slack organisations using app 2014 to 2023
| Year | Organisations |
|---|---|
| 2014 | 30,000 |
| 2015 | 60,000 |
| 2016 | 200,000 |
| 2017 | 330,000 |
| 2018 | 450,000 |
| 2019 | 640,000 |
| 2020 | 750,000 |
| 2022 | 1,000,000 |
| 2023 | 1,100,000 |
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: Users
Microsoft Teams has around eight times as many users as Slack, although Slack reports daily actives and Microsoft reports monthlies.
Slack and Microsoft Teams users 2017 to 2023 (mm)
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
