Salesforce Buys Slack

In 2021 Salesforce paid about $27.7 billion for Slack — its largest acquisition ever, at a price almost nobody called cheap. The logic wasn't really Slack's revenue. It was Microsoft. Teams had launched in 2017, ridden free inside Office 365 to surpass Slack in daily active users, and turned a beloved chat tool into the underdog in a bundling war it was structurally positioned to lose. Salesforce, strong in CRM but missing a front-end collaboration surface, saw something in Slack other than a messaging app.

For founders and operators, this is a case about when buying beats building — specifically when an incumbent with structural advantages is taking ground faster than any organic roadmap can answer. Integration has since been messier than promised, which is part of the lesson. It sharpens how you'd judge whether an acquisition target is genuinely enough to change a strategic outcome, and whether you could integrate it fast enough to matter.