Slack

Stuart Butterfield was building a video game that failed. The internal communication tool his team used during development was better than the game. He shipped the tool instead. Slack launched in 2013 and reached 8,000 companies in its first week without a single sales call. The freemium model was perfectly designed. Free Slack included 10,000 messages of searchable history. Once a team hit that limit, old messages disappeared. The team could keep using Slack for free, but six months of decisions and shared files became invisible. Paying $7.25 per user monthly unlocked everything. The choice was between paying and losing institutional memory.