The widespread application of M2M communications is obvious. There are already many useful services enabled by M2M communications such as video surveillance, smart grid, smart home, connected vehicle, industry automation and smart city. These services are different from traditional Internet services such as e-mail, web browsing and video watching. As a result, we need to understand new charging factors beyond those defined in the past such as amount of data transfer, number of short messages and duration of voice communication. In this paper, we identify new charging factors for M2M communications and analyze their differences with traditional voice and Internet networks. Based on the result of our analysis, new charging models specific to M2M communications are proposed to enable smart data pricing that creates a win-win situation for operators and users.