WhatsApp users cross 2 billion, second only to Facebook

(Reuters) - Facebook-owned messaging app WhatsApp said on Wednesday it has amassed 2 billion users, becoming the second social media platform in the world to hit that milestone.WhatsApp did not specify how it calculated the number of users, but said it had 500 million users in 2014, when Facebook Inc bought the mobile-messaging startup for $19 billion (£15 billion) to boost its popularity, especially among a younger crowd.Facebook has been trying to boost revenue from its high-growth units..