Imagine, if you will, a country of more than 1.3 billion people with no access to Facebook, Instagram, or Twitter. Now imagine that more than half of those people—846 million, to be precise—are using one online social service to chat and share with friends, read news, play games, track their fitness goals, make voice and video calls, shop online, and even pay for lunch. This is not a fantasy. The country is China, and the service is WeChat. With an average of 570 million user