> Slack has ~12-13 mil DAUs, right?
As of September 2019, Slack reported 12 million DAUs [0]. Of course, that is pre-pandemic, and the only figures that Slack has provided regarding demand in 2020 are these tweets [1] from Slack CEO Stewart Butterfield back in March. In those tweets, it mentions that Slack was serving 12.5M simultaneously connected users.
[0] https://slack.com/blog/news/work-is-fueled-by-true-engagemen...