 is quite important. We can see that in South Korea, the in-depth market research resulted in abundant applications for mobile data services. Emotional marketing is also a powerful weapon, which has been proved in China. In South Korea and China, we can see the importance of the trend creation for mobile data services. The operators have been making great efforts in preparing the market for several years. Market segments, customer differentiation, and special branding are effective approaches in opening a new market. Particularly, for the possible pioneer users of new mobile services-the young generation-the operators both in South Korea and China have designed particular service packages and brands and made them become an identity for the young generation. As a result, Cell phones and mobile services are playing an increasingly significant role in the lives of people as a cultural element in China and South Korean. The experience from China and South Korea has shown that customers' prefer- ence and tendency can seriously be influenced by the advertisement of MNOs. The situation that U.S. consumers present little interests in data services can be largely caused by the providers' marketing strategies. In the advertisement of the U.S. pro- viders, there have been a few highlights for mobile data services. Customers have been led to focusing on voice services plans and free or low-price cell phones SO that they do not have deep impression of any mobile data service. But it should be noticed that the process of trend creation needs investment on advertising and market research. At the beginning years, the return on that investment could not be huge. There might be a high risk to explore a new market. In the United States, each MNO is facing tough competition from others. It is dangerous for one com- pany to try changing the preference of the consumers. It might lose its customers because when it is doing this, its rivals are satisfying the current preference. Therefore, operators should pay attention to the balance b