Slack is a tool that helps teams communicate. The company has raised $42.75 million with a valuation of $250 million. Investors in this round include The Social + Capital Partnership, Accel Partners, Andreessen Horowitz, Yelp CEO Jeremy Stoppelman, Anthony Caselena of Squarespace, John Collison of Stripe, Patrick Collison of Stripe, and Om Malik of GigaOM. Slack currently hits around 60,000 daily users and 15,000 paid seats.
The CEO of the company is Flickr co-founder Stewart Butterfield. Slack is almost cash-flow positive and plans to use the funding for hiring and acquiring small teams. Slack had to turn down numerous acquisition offers, including one from Dropbox