Slack CEO Explains Why He Thinks His 8-Month-Old App Is Now Worth $1.1 Billion

There's been so many billion-dollar startups these days that it's almost starting to feel routine in tech.  Slack, an enterprise work collaboration app, is the latest one to join the club. It announced on Friday that it's raising $120 million at a $1.1 billion valuation. It's hard to imagine a company as young as Slack -- it launched publicly in February -- to be worth more than a billion dollars. But when you're growing as fast as it is, especially in the enterprise space, anything is possible...