Facebook announced yesterday that its popular photo-sharing app Instagram now has 400 million monthly active users. More than 75 percent of Instagram users are outside the U.S. (with more than half of the most recent 100 million users living in Europe and Asia). “Facebook’s strategy of creating separate apps appears to be paying off,” suggests The Wall Street Journal. “The texting app WhatsApp, which Facebook acquired for $19 billion in 2014, recently reached 900 million monthly active users.” CEO Mark Zuckerberg recently announced that Facebook’s standalone Messenger app had more than 700 million users.