Business Opportunities, Challenges, Strategies and Executions in Big Data Era--- A Case of Mobile Ads Big Data Cases: Duolingo, Google now, Google Flu Trends, JawBone, AppDynamics, SnapLogic, DropCam, Netflix, Ayasdi, Automatic, Nest, Wealthfront, Zephyr Health, OpenGov 3R: Reach, Richness, Range