This study uses the amount of time users spend on social networking sites (SNSs) to differentiate user groups and investigates the following three issues: (1) the most common behavior of different groups when using SNS; (2) whether users have different perceptions of their social capital on SNSs versus in real-life environments; and (3) whether there are differences in the perceived social capital of different groups. This study discovered that users have different user behavior depending on their amounts of usage. In particular, heavy users tend to be willing to share information and often use application programs associated with SNSs. With regard to perceptions of social capital, the study found that different groups have somewhat different ideas as to what constitutes social capital. We summarize a novel individual social capital systematic behavior and discuss the practical implications of this work and suggestions for future research. Copyright © 2013 John Wiley & Sons, Ltd.