Stewart Butterfield’s Slack Picks Up Spaces, Its First Acquisition

When Stewart Butterfield developed Flickr through his old company Ludicorp in Vancouver, he probably didn’t imagine he’d sell it to Yahoo in 2005. Likewise, he probably didn’t expect he would have developed the most hyped business collaboration app in recent memory, called Slack, via failing at a much beloved multi-player video game, called Glitch.

And yet here he is, acquiring other companies and folding them into his own, a scant 10 years later.

On Friday, Slack announced that it had acquired Spaces, a two-person start-up boot-strapped by Hans Larsen, who previously helped develop Google+ and Chrome for Google, and Simon Vallee, whose earlier start-up OpenCal was sold to Groupon. He also sold a website creation tool called Sitesmasher to Salesforce in 2008.

“Our mission at Slack is to make people’s working lives simpler, more pleasant, and more productive,” read the official announcement on Slack’s blog. “Spaces is clearly aligned with this, and after spending some time together, we reached the conclusion that integrating our products made too much sense to pass up. So in the coming months, we’ll be working on doing just that.”

Spaces is an app that allows collaborators to edit, comment on and share documents, adding links, texts and images to them in real time.

Terms of the deal, done exclusively in stock, were not disclosed. This is Slack’s first acquisition.

Slack only officially launched in February, and today has over 200,000 users, a figure that has more than doubled in the past three months, probably owing to a bout of breathless hype that appeared in Wired magazine in August.

The workplace productivity app has 60,000 paying customers, including Airbnb, eBay, AOL and Adobe. Slack charges $7 per month per user for full functionality. Its total customer base is 200,000.

Slack allows users to collaborate on documents, view a document’s editing history, and drop links and objects into a document, using Dropbox and Google Drive for file sharing.

In April, Slack raised $42.75 million from Andreessen Horowitz, Accel Partners and Social + Capital. Butterfield intends to expand his crew to 53 and to hire a vice-president of marketing.