1. A method for identifying a key influencer in a social media, said method comprising: compiling a user interest profile by analyzing a historical message stored in a database utilizing a topic modeling approach to thereafter generate social graph data; performing an influence measuring process based on said social graph data utilizing an influence measuring module and a data intensive distributed application module to identify a set of key influencers in a particular topic area by considering time stamp information; and assessing an impact of user communication with respect to growth of a conversation within a predefined time interval in order to predict a message propagation speed and coverage in a social network and permit efficient targeting of said message to said key influencer of a targeted community.