Slack, which has long been seen as a possible IPO candidate, says it now has more than 8 million daily active users. On the paid front, it says it has more than 3 million users, including 65% of the Fortune 100.

Why it matters: Slack's business is managing workplace communications, an area also coveted by Google, Microsoft and Salesforce, meaning the company needs to stay ahead of the pack. CEO Stewart Butterfield told me last year that he is running the company so it could go public, but when it will is another matter.