This document summarizes key information about the workplace communication platform Slack. As of May 2018, Slack had 8 million daily active users, 3 million paid users, and an annual recurring revenue of $200 million, though it was not yet profitable. Its estimated valuation was $8.3 billion. Slack's "secret sauce" includes features like customization for individuals and teams. Competitors include Microsoft Teams, Google Hangouts Chat, and Skype for Business, though Slack differentiates itself through greater customization capabilities. The document predicts that Slack may go public in 2019 and continue acquiring other companies.