Slack

Stewart Butterfield's team was building a video game called Glitch that failed. The internal chat tool they built for the game succeeded beyond anything imaginable. Slack launched in 2013 and reached $27.7 billion in value when Salesforce acquired it in 2021 — making it the most expensive failed-game pivot in history. Slack didn't just replace email for 750,000+ organizations; it created "channel culture," where work conversations became searchable, organized, and asynchronous. The downside: Slack notifications have replaced email anxiety with a new, more persistent form of digital stress.