Today the social-networking giant will host an event in London to unveil a new product aimed at business users. Having signed up about 1.7 billion consumers, Facebook is looking for new sources of growth. Facebook at Work, a separate service, is a communications and messaging tool for corporate use. But although the move makes business sense, success is far from guaranteed, for three reasons. First, it faces a lot of competition: many other firms—including Microsoft, Atlassian and Slack—already offer collaboration tools for workers and have existing relationships with customers. Second, Facebook has built its success engineering and acquiring highly addictive products that hook consumers; designing systems for businesses is not its forte. Third, companies are likely to regard Facebook as a distraction rather than as a productivity tool. Facebook is asking lots of firms to be its friend; the question now is whether they will accept its request.