It’s said that Microsoft CEO Satya Nadella and Bill Gates were part of the group unconvinced of the mega-acquisition, instead wanting to allocate more resources to Microsoft's own video and voice calling service Skype, which it acquired for $8.5 billion in 2011.
The Slack we know today was only launched in mid-2013 and has quickly risen to prominence in both the startup world and the workplace productivity market. The company recently reported annual recurring revenues of over $64 million and daily active user growth from 500,000 in early 2015 to around 2.3 million currently. Although some may say the $8 billion price tag was rather high—Slack was valued at $3.1 billion with its raise last May—it will be even costlier if Slack grows into a serious competitor of Microsoft's business products. Time will tell if the decision to not move forward with the purchase of Slack may come back to bite the tech giant.