Sales reps, suppliers, and Marketing Analytics in Action: Market Share Marketing managers often keep a close eye on market share, comparing how market share changes over time and typically sorting out market share in different geographic locations. Consider the data below, which show the Apple iPhone's market share in four countries in the three months ending December 2017 and 2018. iPhone Market Share December 2018 December 2017 Market Share Change Country United States 43.9% 43.7% 5.5 Mexico 4.4 -0.2% +1.1 -5.3 -8.8 China 28.6 23.3 46.4 Japan 55.2 1. What insights would this provide for a marketing manager with responsibility for global sales of the iPhone? 2. Speculate on why the iPhone's market share declined so much over one year in China and Japan. 3. Why do you think market share for the iPhone is much higher in the United States and Japan as compared to Mexico and China? Look at data in Exhibit 3-3 for ideas. 66