Slack will now let users make video calls with Microsoft Teams - its biggest competitor - from directly within the Slack app

• Slack announced that it is officially launching an integration with Microsoft Teams video calling feature, allowing users to launch video calls in Microsoft Teams directly from Slack.
• CEO Stewart Butterfield told Business Insider last month, before the integration was officially announced, that Slack already has integrations with many other video calling apps, like Zoom and Cisco WebEx, so this integration with Microsoft Teams is meant to give users more choice.
• While Slack and Microsoft Teams often compete, Butterfield said that 70 percent of Slack's customers are also Microsoft customers and sometimes use Teams for video calling.
• Slack said in the past month it's seen a 350 percent increase in calls made or received in Slack, including using Slack's own limited calling feature and via integrations with apps like Zoom and Cisco WebEx.
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Slack announced that it is officially launching an integration with Microsoft Teams video calling feature, a little less than a week after CEO Stewart Butterfield said the company was working on it.

Butterfield told Business Insider last month, before the integration was officially announced, that Slack already has integrations with many other video calling apps, like Zoom and Cisco WebEx, so this integration with Microsoft Teams is meant to give users more choice on what they want to use for video conferencing.

"So just like we already integrate with Zoom, we already integrate with Cisco WebEx, we want to make an integration with those Teams calling functionalities so people can answer calls," he told Business Insider at the time. "It's basically bringing Teams to parity with the other voice and video calling services."

This might be confusing because Slack and Microsoft Teams often compete for customers, but Butterfield thinks people actually misunderstand how they compete. In his mind Slack and Teams are very different products, used for different purposes.

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He said 70 percent of Slack's customers are also Microsoft customers and use its suite of productivity tools. The main use case they've seen for Microsoft Teams is video calling. Slack has limited video and voice calling features built into the product, but it caps at 15 people per call, so they're focused on building integrations with existing applications for video calling.

The bottom line, Butterfield said, is while Microsoft Teams might consider Slack its rival, Slack doesn't see it the same way.

"I think we don't really compete as much with customers. That's not to say that we don't ever, because four of the five biggest enterprise deals we did last quarter were head to head Teams vs Slack. But I think much more of the time, it's Slack versus email," he said.

In other words, corporate customers often think of Slack as an alternative to email for internal communications, according to Butterfield. That's the transition Slack is focused on helping people through, which is even more important with the rise in remote work around the world.

Slack said in the past month it's seen a 350% increase in calls made or received in Slack, including using Slack's own limited calling feature and via integrations with apps like Zoom and Cisco WebEx. Now Microsoft Teams will be an option as well.

Slack is also making it possible to call into any of the existing voice apps it integrates with using a phone number directly within Slack.

"Whatever tools you use, wherever you are, and on whatever device, we want them to work seamlessly with Slack. Having all your software at your fingertips can help you stay connected and productive, and in the past month we've seen that our users have nearly tripled the rate at which they integrate their tools in Slack." said Brian Elliott, VP & general manager of the Slack Platform.

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