Slack: When You Grow So Big the Sharks Come for You

by Shannon Peel

Every brand story has a moment when everything changes. For Slack, that moment came on December 1, 2020, when Salesforce announced it would pay $27.7 billion to acquire the workplace messaging platform that had once been crowned the fastest-growing B2B software application of all time. It was a number that felt like triumph.

This is the story of how one of the most beloved Canadian products in enterprise software history got here, what happened next, and what it tells us about competing with Big Tech when the rules of the game are not in your favour.

The Beginning: A Gaming Company That Accidentally Built a Revolution

Stewart Butterfield was building a video game. His company, Tiny Speck, was working on a game called Glitch when the internal communication tool they created to coordinate the team turned out to be more interesting than the game itself. In 2013, they pivoted. Slack, which stood for Searchable Log of All Conversation and Knowledge, launched publicly in 2014 and grew at a speed that left the technology industry stunned.

It became a verb. People did not say "send me a message," they said "Slack me." That kind of linguistic adoption, the verb status Butterfield himself considered one of his finest accolades, is not something you can manufacture with a marketing budget. It is what happens when a product genuinely changes how people work and they cannot imagine going back.

By the time Slack went public via a direct listing in June 2019, the company was valued at approximately $23 billion. It had over 10 million daily active users, a passionate developer community, and a product that people genuinely loved. That is a rare combination in enterprise software, where most products are tolerated rather than celebrated.

The Problem: A Giant With a Bigger Bundle

The trouble with building something people love is that larger, better-resourced companies notice. And Microsoft noticed.

In 2017, Microsoft launched Teams, a workplace collaboration tool embedded directly into its Microsoft 365 suite. The product was, by most objective measures, not as good as Slack. Review platforms like TrustRadius and G2 Crowd consistently rated Slack higher on product quality. But Microsoft did not need a better product. It needed a better bundle.

Microsoft gave Teams to existing Microsoft 365 subscribers for free, bundled inside software that enterprises were already paying for and already had deployed across their organizations. The question IT departments had to answer was not "which is the better product?" It was "do we really want to pay for a separate subscription when we already have something that does the job inside our existing stack?"

That is a question Slack could never win, no matter how good the product was. By late 2020, Microsoft Teams had amassed over 75 million daily active users, compared to Slack's 13 million. The numbers tell the story.

Slack did not go quietly.

In July 2020, it filed an antitrust complaint against Microsoft with the European Commission, arguing that Microsoft was illegally tying Teams to Office 365 and using its dominant market position to crush a competitor. Butterfield himself told the Wall Street Journal that he believed Microsoft viewed Slack as an existential threat. The complaint was legitimate and the concern was real, but the regulatory process moves slowly and the market moves fast.

Kate Leggett, an analyst at Forrester Research, summarized the situation when the Salesforce deal was announced. "Microsoft Teams is eating Slack's lunch," she said.

Why Slack Sold: The Honest Answer

Butterfield, to his credit, never admitted publicly that Microsoft was the reason for the sale. He bristled at the narrative. "It almost seems sometimes like it's a matter of faith for people," Butterfield said in a 2020 interview cited in an SEC filing. "It's not based on any empirical evidence, it's just people think Microsoft is a bigger company, and they have a huge channel, and so they'll inevitably win, despite the fact that we win."

There is something admirable about that stubbornness. There is also something that does not quite add up.

Before news of the Salesforce deal leaked, Slack's stock had lost approximately a quarter of its value since going public. It was trading near its original listing price of $26 per share despite years of strong user growth and genuine product love. Investors were not convinced Slack could defend its market position against a company willing to give away a knock off for free as part of a $150 per user per year software bundle.

The deal itself came together in an unexpected way. Butterfield approached Salesforce President and COO Bret Taylor during the early days of the pandemic, not to sell the company but to try to buy something from Salesforce, a product called Quip. Taylor said he would get back to him. He did, six months later, with a different kind of conversation.

"He said he'd get back to me, and then got back to me six months later or so," Butterfield said in an interview with TechCrunch. "At that point, the conversation flipped and the companies began a series of discussions that eventually led to Salesforce acquiring Slack."

Slack sold because the market made it very difficult to win as an independent company against a competitor with Microsoft's distribution advantages. The $27.7 billion offer was the safe play and an exceptional payload for founders who built something extraordinary.

Why Salesforce Bought: The Missing Communication Layer

Salesforce CEO Marc Benioff was not shy about the strategic rationale. "Stewart and his team have built one of the most beloved platforms in enterprise software history," Benioff said in the official press release issued December 1, 2020. The acquisition, Salesforce argued, would create "the operating system for the new way to work."

That framing was strategic, not accidental. Salesforce had spent years building a Customer 360 platform that covered CRM, marketing automation, customer service, data visualization through Tableau, and API integration through MuleSoft. What it did not have was the communication layer, the place where people actually talk to each other and get work done.

Slack was that layer.

Bret Taylor articulated it clearly in a 2020 interview. The deal was worth the money, he said, because it allowed Salesforce to bring together all the pieces of their platform, and having Slack gave Salesforce a missing communication layer on top of its other products, something especially important as interactions with customers, partners and employees had become mostly digital.

The acquisition was at least partially about catching Microsoft, according to Battery Ventures general partner Neeraj Agrawal, who spoke with TechCrunch at the time of the deal. Salesforce had already acquired Tableau to compete with Microsoft Power BI and MuleSoft to compete with Azure integration services. Adding Slack was the next move in a chess match that Benioff had been playing with Microsoft for years.

Wedbush Securities analyst Dan Ives described the core logic plainly: the deal was driven by the need to keep pace with the "cloud behemoth" Microsoft and its popular productivity tools, including Office 365 and Teams.

The deal closed on July 21, 2021, after regulatory approval from the Department of Justice, which had initially requested additional information before concluding the acquisition did not raise significant antitrust concerns.

What Happened Next: Culture Clash in Slow Motion

Here is where the story gets complicated, and where it stops looking like a success story and starts looking like a cautionary tale about what happens when a product-first, bottom-up, developer-loved company gets absorbed into an enterprise sales machine.

The first sign of trouble came quietly, in the way that first signs usually do. Post-acquisition, Slack employees noticed that the integration of cultures was not going the way they had hoped. The worry was not just about org charts or reporting structures. It was about identity.

In January 2023, during an all-hands meeting with Slack employees, Butterfield put it directly. "The problem has been, there's no incorporation of the Slack culture into the Salesforce culture," Butterfield said, according to an audio recording of the meeting obtained by Fortune. "And unless there is some element of that, then it's not integration in any sense. It's just the elimination."

That quote landed hard, because Butterfield delivered it just weeks after announcing he was leaving the company. His departure came exactly two years after the Salesforce deal was announced, which was also the end of the stay period typically required in acquisition agreements. Butterfield said he was leaving to spend time with his family, work on personal projects, and, in his own words, pursue his fantasy of gardening. But the timing was not lost on anyone paying attention.

He was not the only one leaving. Slack CPO Tamar Yehoshua, SVP of marketing Jonathan Prince, and Salesforce co-CEO Bret Taylor, who had brokered the deal, all departed within days of each other in December 2022. Shortly after, Tableau CEO Mark Nelson also announced his exit. The executive exodus was significant enough that Salesforce shares fell more than four percent in a single trading day.

Butterfield called the simultaneous departures with Taylor a "weird coincidence" in an internal Slack message. Whether you believe that framing is up to you.

His replacement was Lidiane Jones, a longtime Salesforce executive who had been with the company since 2019. Jones herself left in 2023 to become CEO of Bumble, and was replaced by Denise Dresser, who led Slack until she departed in December 2024 to become Chief Revenue Officer at OpenAI. That is three CEOs in roughly three years, a pace that does not suggest stability.

Did Salesforce Change Anything?

The short answer is yes, and the changes were not all welcome.

Slack arrived at Salesforce with approximately 2,500 employees. Salesforce, which had gone on a pandemic-era hiring spree that swelled its workforce from 50,000 to 79,000 employees, began a series of layoffs starting in November 2022 and continuing into 2023, when it cut approximately 10% of its total workforce, roughly 8,000 roles. Slack employees were among those affected. As one former account executive wrote on Glassdoor in 2024, the post-acquisition experience was "very painful, going from Slack to Salesforce was extremely disruptive, many leaders and talented AEs left, and there is still unclear direction from leadership."

The product-side integration also moved more slowly than Salesforce had signalled. Investors and analysts had expected Slack to become deeply embedded in the Salesforce Customer 360 platform, creating seamless workflows between CRM data and the communication layer where sales and service teams actually operated. That vision took longer to materialize than expected, and by 2024, there were activist investors pushing Salesforce to consider divesting both Tableau and Slack.

The AI revolution complicated the picture further. Salesforce had pivoted aggressively toward AI with the launch of Agentforce, its autonomous AI agent platform, in October 2024. The company hit $900 million in Data Cloud and AI annual recurring revenue in fiscal year 2025, growing 120% year-over-year, according to Salesforce's own SEC filings. But the spotlight was on Agentforce and Data Cloud, not Slack.

Salesforce co-founder and CTO Parker Harris was eventually brought in as Slack's Chief Engineering Officer, a sign that the company recognized it needed to more deliberately invest in the product's technical development.

By fiscal 2025, Salesforce CEO Marc Benioff was publicly naming Slack as one of the core components of a unified enterprise AI platform, citing Agentforce, Data Cloud, Customer 360, Tableau, and Slack as all built on one trusted foundation. Whether that represents genuine strategic centrality for Slack or Benioff making the best of a $27.7 billion investment is a question the market has not fully answered.

The Real Story Underneath

Every acquisition tells two stories. The public story is about strategy, synergies, and competitive positioning. The real story is about what happens to the people, the culture, and the product when a company built one way gets absorbed into a company built a very different way.

Slack was a product-first company. It grew organically, from the bottom up, because developers and small teams loved it so much they convinced their companies to adopt it. Its culture was shaped by that origin, scrappy, opinionated, consumer-minded in a world full of enterprise solutions that prioritized features over experience.

Salesforce is one of the most successful enterprise software companies in history, built on a direct sales model, strategic partnerships, and the kind of flashy conference-driven marketing that produces Dreamforce, an annual event that draws tens of thousands of enterprise software buyers to San Francisco. It is excellent at what it does. It is just a fundamentally different kind of company.

Butterfield's observation that there was no incorporation of Slack culture into Salesforce culture, that it was elimination rather than integration, describes a failure that happens in acquisitions more often than anyone wants to admit. The acquirer pays a premium for what a company is. Then, systematically and often unintentionally, they change the things that made it worth the premium.

The story is not over. Slack still has millions of daily active users, a strong product, and a parent company with enormous resources and genuine motivation to make the investment pay off. The integration with Agentforce could yet prove to be the communication layer that makes AI-driven workflows actually work for enterprises. Benioff's vision of a unified platform is coherent, even if the execution has been messy.

But the lesson in this story, the one that matters for anyone building a brand, a product, or a company, is that market position is not enough if the economics of the market are working against you. Slack had better product ratings than Teams. It had a more devoted user community. It had verb status. None of that could overcome Microsoft's ability to bundle a competitor for free inside software that enterprises were already paying for.

Sometimes the story is not about who builds the best product. It is about who controls the distribution.

The Vancouver Chapter: Where It All Started, Reduced to a Footnote

Slack began in Vancouver. That is not a trivial detail. Stewart Butterfield and his co-founders built Tiny Speck in this city, in a Yaletown heritage building on Hamilton Street with moss walls, locally sourced furniture, and mobile meeting cubes on wheels. It was the kind of office that tells you everything about the culture of the company inside it, thoughtful, creative, and deeply human.

At its peak, Slack expanded its Vancouver footprint significantly, leasing 34,000 square feet at Bentall 5 on Burrard Street in addition to the original Yaletown space. The city was not just a satellite office. It was where the idea was born.

Today, LinkedIn shows approximately 237 people in Vancouver connected to Slack. There is no senior Canadian leadership. There is no decision-making authority. The head office is in San Francisco, the parent company is in San Francisco, and the people who determine what Slack becomes next are in San Francisco.

That is what absorption looks like in practice. It is not always a dramatic shutdown or a public announcement. Sometimes it is quieter than that, a gradual thinning of presence, a reduction in headcount, a head office that moves further and further away from the place where the original idea caught fire. The Vancouver team still exists, and the work they do still matters, but the soul of the company, the founders, the culture, the decision-making, left the building a long time ago.

Slack started in Vancouver as an accident, a communication tool built to help a small team make a game that nobody ended up playing. It grew into something millions of people used every day and genuinely loved. It was acquired for $27.7 billion, absorbed into an enterprise giant, and the city where it all started is now home to 237 employees with no seat at the table where the company's future gets decided.

That is not a tragedy. It is just business. But it is worth saying out loud, because Vancouver built something extraordinary here, and that story deserves more than a footnote.

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Shannon Peel is a Brand Narrative Strategist, a Vancouver-based brand strategy and Communications Strategist. She builds strategic brand storytelling ecosystems, the systems that help businesses, executives, and thought leaders earn authority, credibility, and citations across the digital landscape, including AI-generated answers. Shannon writes about brand strategy, marketing, the Canadian economy, business resilience, and the evolving gig economy.