Microsoft explains where its new Slack-killer fits in with its $1.2 billion Yammer acquisition

This week, we finally got to see Microsoft Teams - a new work chat app that will compete with the likes of Slack and Atlassian HipChat.

Teams will be a part of the Office 365 subscription service, where companies pay a monthly or yearly fee and get access to a whole range of Microsoft productivity software, including Outlook, Word, Excel, and PowerPoint.

But Teams isn't the only social product in Office 365. Back in 2012, Microsoft paid $1.2 billion for Yammer, a social networking tool for the enterprise cofounded by current Zenefits CEO David Sacks. And Microsoft confirms that even with the rise of Teams, Yammer isn't going anywhere.

Really, Microsoft says, Teams and Yammer scratch different itches within Office 365.

• Yammer acts a little bit more like a bulletin board (or your Facebook news feed), where people can post status updates, links, and documents, and chat around them. Microsoft corporate VP of Office 365 marketing Ron Markezich tells me that internally at Microsoft, it's how executives like CEO Satya Nadella post updates to the whole company.
• Microsoft Teams is more like Slack or any other chat program: It's more about on-the-fly, free-ranging conversations for groups of smaller teams, though you can still post documents and web apps and talk about those, too.

Since the acquisition, Yammer has always been kind of an odd duck in the larger Microsoft picture: It was only earlier this year, almost four years since the acquisition, that Microsoft started making Yammer available to Office 365 customers rather than making it available as a separate product.

Markezich says that, sure, Microsoft could have built the Teams functionality into Yammer, but the risk was that the social feed would get "clogged" and overcomplicated.

"It's a way to keep Yammer pure and clean," Markezich says.

In fact, Microsoft tells Business Insider that Teams was built entirely in-house, without using any technology from acquisitions like Yammer or smaller buys like Ray Ozzie's Talko. The goal was to complement Yammer with something that enabled more spontaneous collaboration that the more traditional social news feed.

"Yammer serves a great purpose, which is the social network," Markezich says. "It's not the place where social interactions happen."

Microsoft Teams is currently available in preview, and will launch for all Office 365 business customers in early 2017.