In the era of Web 2.0, with the social media's advantage, many creative e-commerce modes based on online or offline social networks emerged, such as social buying and viral marketing. Social network analysis provides a powerful set of tools for modelling social networks to understand their structure and behaviour. However, current challenge is that the target environments involve large amounts of relational data that characterise multi-entities, time-sensitive, decision-making situations. To understand the structure and the dynamic mechanisms of the complex real-world system, the researchers need innovative network modelling approaches and analysis techniques. This paper first proposes a social buying metanetwork model, and then provides a methodology framework integrated business intelligence techniques with dynamic network analysis tools, finally the case study describes the process on metanetwork modelling, dynamic network analysis, and buyer behaviour pattern mining. The empirical results can help managers identify problems and take appropriate strategies or measures.