NTT DoCoMo's i-mode service is seen as one of the most successful examples of mobile business. This chapter describes parts of the business model of i-mode and sketches various attempts to explain i-mode's success. In this chapter the relevant technological standards for each of the four interfaces in the i-mode world are identified, and their degree of openness is determined. NTT DoCoMo uses the iHTML mark up language, which is based on compact HTML (cHTML). It holds a market share of 61.9 percent in the Japanese mobile Internet market. It used their advanced knowledge of the personal digital cellular(PDC) standard to develop superior handsets in cooperation with four closely associated manufacturers. In order to build a digital network based on PDC, the PDC protocol had to be ratified by the Japanese Association for Radio Industry Businesses (ARIB). Finally, a central aspect of NTT DoCoMo's value scope management is the architecture of information spheres it has established for the i-mode service.