Slack transformed workplace communication when it launched in 2013, replacing email with real-time chat channels organized by project, team, or topic. Founded by Stewart Butterfield (Flickr co-founder) from the ashes of failed gaming startup Glitch, Slack reached 1 million daily active users within its first year and became synonymous with remote-first company culture.
The Revolution
Before Slack, internal communication meant email chains, fragmented instant messaging (Skype, Google Chat), and missed context. Slack unified conversations into searchable, threaded channels with integrations (Google Drive, Jira, GitHub). The tool’s playful UI (emoji reactions, custom emojis, GIF support) made work feel less corporate, appealing to startups and tech companies.
Explosive Growth
Slack IPO’d in June 2019 via direct listing at $23B valuation, with 10 million daily active users across 600K+ organizations. The pandemic accelerated adoption as remote work became standard. By 2020, Slack had 12.5 million DAUs and $902M annual revenue. Salesforce acquired Slack for $27.7B in December 2020, its largest acquisition ever.
The Dark Side
Slack’s “always-on” culture created new workplace stress. Employees felt pressure to respond instantly, blurring work-life boundaries. Notifications became overwhelming (the “purple dot” anxiety). Critics argued Slack increased interruptions (fragmenting deep work) and created FOMO (missing important discussions in side channels).
Cultural Impact
#Slack spawned entire ecosystems:
- Slack-first communities (Superpath, On Deck, invite-only networks)
- “Slack ettiquette” guides (thread replies, @channel vs @here, status emojis)
- Workplace communication debates (async vs sync, email vs Slack, meeting-free days)
- Memes about Slack overload (“I have 47 unread channels”)
The tool validated that millennials/Gen Z preferred chat over email, influencing Microsoft Teams (launched 2017 to compete), Discord (work-friendly features), and asynchronous tools (Loom, Notion, Linear).
References
- Slack IPO: The Hype and the Peril - Wired, June 2019
- Salesforce to Acquire Slack for $27.7B - Salesforce, December 2020