Earlier this week, Microsoft confirmed its Microsoft Teams workplace chat service now has over 20 million active daily users. This milestone sees the platform seemingly move further ahead of market rival Slack.

As we have previously seen, whenever Microsoft Teams hits a milestone, Slack is not to far away to point out its own situation. That’s the case again with Slack telling Thurrott that its service continues to top Teams where it counts.

“As we’ve said before, you can’t transform a workplace if people aren’t actually using your product,” a Slack spokesperson told me. “Slack continues to see unmatched engagement on our platform with 5+ billion weekly actions, including 1+ billion mobile actions. Among our paid customers, users spend more than 9 hours per workday connected to our service, including spending about 90 minutes per workday actively using Slack.”

Slack is arguing that Microsoft Teams numbers are not that impressive at all. Microsoft says its service has 20 million active daily users and 27 million voice or video meetings were held last month. Slack says this means only a little over 1 monthly voice/video call per users.

Microsoft says Teams had 220 million filed edited, stored, or opened on its platform last month. As Slack points out, this would only mean 11 monthly actions related to files per active daily users.

Slack Criticism

Slack has used every opportunity to criticize Microsoft Teams. Considering Microsoft’s resources, attack has been the best form of defense for Slack.

CEO Stewart Butterfield previously called Microsoft Teams the Google+ of workplace chat solutions, while also drawing comparisons with Microsoft’s own Bing: “Tens of billions of dollars into that [search engine] and I don’t know what their market share is now — 9% or something like that,” he noted.

The company also argued businesses prefer to use its platform, while recently claiming Microsoft has been “unsportsmanlike” in competing with Slack.