Slack: the internal chat tool from a failed game becomes a $60M-funded work platform

Stewart Butterfield's Tiny Speck spent years building the browser MMO Glitch with a team split between San Francisco and Vancouver; the messaging tool they built to coordinate themselves worked so well that, when the game was shut down in 2012, it was the most valuable thing the company had.

Build the tool your own team needs, then make it the product: after the game Glitch flopped, Tiny Speck's internal messaging system became the workplace app Slack.

The team rebuilt the tool as Slack — channels, search, integrations, a playful Slackbot — and launched it publicly in February 2014. It grew bottom-up inside companies before IT departments signed off, with zero advertising.

By August 2014 Slack was growing 5–10% a week with 120,000+ daily users, 38,000 paying teams in 2,000 organizations, 93% retention and $60M raised — the fastest-growing business app of its era, born from a failed game.

Slack began as the internal messaging system of Tiny Speck, the company Stewart Butterfield founded to build the browser-based online game Glitch. As SitePoint recounted from a talk by Slack's customer-experience director, the tool was built during the game's development; Glitch closed in 2012, but the communication tool was the thing the team couldn't give up.

It was the second time Butterfield's pattern had produced a business: Flickr itself had been broken out of his earlier failed game, Game Neverending. For Slack, the team applied the craft from Glitch — making boring interactions feel fun and irreverent — to business software, with channels, powerful search, integrations and a cheerful Slackbot.

Slack launched publicly in February 2014 and grew entirely by word of mouth, at 5–10% per week. By August it had more than 120,000 daily users, 38,000 paying organizations out of 2,000 companies, about $1.5 million in revenue and a 93% retention rate, and it had raised some $60 million in venture capital — $43 million of it in April 2014.

The tool was proven by the team's own daily use before anyone else saw it — years of dogfooding replaced guesswork.

A failed game forced the company to learn what people actually want, lessons business-software incumbents never had.

The playful, game-crafted design made a work tool people wanted to open, not a chore they tolerated.

The internal pain — a distributed team's messy communication — was a real, universal market need.

Zero-advertising growth meant the product itself did the selling, the strongest possible validation of the idea.

A tool your own team refuses to stop using is product-market fit with working code: your internal pain is a real market, and a failed project can still hand you the winning idea.

Slack went on to define workplace chat: 10 million daily active users by January 2019, with 65 of the Fortune 100 among its customers, and a 2019 public listing at a $23 billion opening valuation. The Glitch origin story became the canonical example of a pivot, repeated in case studies and founder talks. Salesforce completed a $27.7 billion acquisition of Slack in July 2021, and Butterfield stayed on to lead the unit.