• Home
  • Latest
  • Fortune 500
  • Finance
  • Tech
  • Leadership
  • Lifestyle
  • Rankings
  • Multimedia
TechBrainstorm Tech

Slack CEO Stewart Butterfield Isn’t Worried About Battling Chief Rival Microsoft

By
Aaron Pressman
Aaron Pressman
Down Arrow Button Icon
By
Aaron Pressman
Aaron Pressman
Down Arrow Button Icon
July 15, 2019, 10:14 PM ET

Corporate messaging service Slack has some advantages over its chief rival, Microsoft, despite Slack having fewer users, CEO Stewart Butterfield says.

“It’s hard to maintain a real focus on quality, on user experience, and the bigger you get the harder it is,” Butterfield said in an interview at Fortune’s Brainstorm Tech conference in Aspen, Colo. on Monday.

Since debuting its workplace messaging app five years ago, Slack has quickly become a popular alternative to communicating by email, attracting 600,000 customers in 150 countries. But it faces a tough adversary in Microsoft, the leading provider of corporate office software, including Outlook email and the Slack-like Teams messaging app.

Asked whether his company was in danger of being crushed by Microsoft, Butterfield pointed out that a young Microsoft overtook IBM at the height of its domination. Then Google defeated Microsoft in Internet search when it was just an upstart, Butterfield noted, and then was itself defeated in social networking by the then-tiny Facebook.

“The lesson that we take from that is that a smaller company if it has real traction with customers in some cases has a bit of an advantage against a large incumbent with multiple lines of business,” he said. On the other hand, “there’s plenty of (small) companies have been crushed, as well,” he conceded.

Slack’s stock lost 4% in one day last week after Microsoft disclosed it had 13 million daily active users for its competing app, Teams. That’s more than Slack, at least according to its most recent disclosure as of the end of January, when it had 10 million such users.

And last month, Microsoft banned its own employees from using Slack internally, citing potential security concerns. Microsoft has a long track record of defeating rivals with the help of its vast array of offerings and connections with almost every major company in the world.

But Butterfield also praised his rival, saying Microsoft was “an incredible company” and that its Azure cloud services unit has been “a great partner” for Slack. Slack uses Azure as a backbone for its own service.

“They’re big enough that they end up working with and competing with all kinds of people around the world,” Butterfield said of Microsoft. “Whatever Microsoft does, we’re still going to do the same thing for customers…it doesn’t really matter what Microsoft does.”

Slack was among a wave of notable tech companies that have gone public this year including Lyft, Uber, Pinterest, Zoom Video, and PagerDuty. But all of the others did a traditional Wall Street initial public offering, in which a syndicate of banks sells new shares to investors and then delivers the proceeds to the company—minus fees. But Slack did a direct listing, issuing no new shares and simply allowing its existing shareholders, including its employees, to sell their holdings in the offering.

Slack didn’t go the traditional IPO route largely because it didn’t need to raise any more money, Butterfield said.

“We took advantage of the very generous funding environment over the last five years and had over $800 million on the balance sheet,” he said. “We didn’t need to raise any money, but we still wanted to be public.”

More must-read stories from Fortune Brainstorm Tech 2019:

—The real reason Walmart needs its stores in order to compete with Amazon

—Ancestry CEO talks genetic data privacy and the business of DNA testing

—Analyst: Expect more tech regulation despite declining user privacy concerns

—Barbie movie will cast minority actors, according to Mattel CEO 

—Quantum computers might save the world—if there are workers to build them

Catch up with Data Sheet, Fortune’s daily digest on the business of tech.

About the Author
By Aaron Pressman
See full bioRight Arrow Button Icon

Latest in Tech

Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025

Most Popular

Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Fortune Secondary Logo
Rankings
  • 100 Best Companies
  • Fortune 500
  • Global 500
  • Fortune 500 Europe
  • Most Powerful Women
  • Future 50
  • World’s Most Admired Companies
  • See All Rankings
Sections
  • Finance
  • Fortune Crypto
  • Features
  • Leadership
  • Health
  • Commentary
  • Success
  • Retail
  • Mpw
  • Tech
  • Lifestyle
  • CEO Initiative
  • Asia
  • Politics
  • Conferences
  • Europe
  • Newsletters
  • Personal Finance
  • Environment
  • Magazine
  • Education
Customer Support
  • Frequently Asked Questions
  • Customer Service Portal
  • Privacy Policy
  • Terms Of Use
  • Single Issues For Purchase
  • International Print
Commercial Services
  • Advertising
  • Fortune Brand Studio
  • Fortune Analytics
  • Fortune Conferences
  • Business Development
  • Group Subscriptions
About Us
  • About Us
  • Editorial Calendar
  • Press Center
  • Work At Fortune
  • Diversity And Inclusion
  • Terms And Conditions
  • Site Map
  • About Us
  • Editorial Calendar
  • Press Center
  • Work At Fortune
  • Diversity And Inclusion
  • Terms And Conditions
  • Site Map
  • Facebook icon
  • Twitter icon
  • LinkedIn icon
  • Instagram icon
  • Pinterest icon

Latest in Tech

lancaster
AIschools
Two private school boys get probation for using AI to create 350 fake nudes of their classmates
By Mark Scolforo and The Associated PressMarch 25, 2026
3 hours ago
melania
PoliticsWhite House
Enter Melania Trump, escorted by humanoid robot: ‘I’m Figure 03, a humanoid built for the United States of America’
By Darlene Superville and The Associated PressMarch 25, 2026
3 hours ago
bernie
AICongress
Bernie Sanders and AOC launch bill to ban new data-center construction
By Matthew Daly and The Associated PressMarch 25, 2026
4 hours ago
Big TechSocial Media
A court just ruled that tech addiction is real—and dangerous. It could be Meta and YouTube’s Big Tobacco moment
By Kristin StollerMarch 25, 2026
4 hours ago
Warner gestures
AIAmerican Politics
New college grad unemployment will spike to 35% in 2 years, senator warns, forcing ‘Dario, Sam’ to quit AI fear-mongering
By Jacqueline MunisMarch 25, 2026
6 hours ago
Big TechMeta
Meta and YouTube found liable in landmark child social media harm case, ordered to pay $3 million—with punitive damages still to come
By Kaitlyn Huamani, Barbara Ortutay and The Associated PressMarch 25, 2026
6 hours ago

Most Popular

Magazine
The youngest-ever female CEO of a Fortune 500 company is fighting Trump's cuts to keep Medicaid strong
By Fortune EditorsMarch 24, 2026
2 days ago
Commentary
The Treasury just declared the U.S. insolvent. The media missed it
By Fortune EditorsMarch 23, 2026
2 days ago
Success
Palantir’s billionaire CEO says only two kinds of people will succeed in the AI era: trade workers — ‘or you’re neurodivergent’
By Fortune EditorsMarch 24, 2026
1 day ago
Success
The job market is so bad that ‘reverse recruiters’ are charging $1,500 a month just to help people look for jobs
By Fortune EditorsMarch 25, 2026
17 hours ago
Energy
Nobel laureate Paul Krugman calls it 'treason': $580 million in suspicious oil futures traded minutes before Trump's Iran reversal
By Fortune EditorsMarch 24, 2026
1 day ago
Success
JPMorgan has started monitoring the keystrokes, video calls, and meetings of its junior investment bankers—and they say it's for employee well-being
By Fortune EditorsMarch 24, 2026
1 day ago

© 2026 Fortune Media IP Limited. All Rights Reserved. Use of this site constitutes acceptance of our Terms of Use and Privacy Policy | CA Notice at Collection and Privacy Notice | Do Not Sell/Share My Personal Information
FORTUNE is a trademark of Fortune Media IP Limited, registered in the U.S. and other countries. FORTUNE may receive compensation for some links to products and services on this website. Offers may be subject to change without notice.