Chief Minister Mamata Banerjee might have been a late entrant to the world of Twitter, but in about 15 months she has become one of the most social media-savvy politicians of the East - tweeting regularly about events and people. While her active participation had a positive effect on her party's handle, the Left leaders seemed to be no match. State units of national parties such as BJP and Congress are also trying to catch up. In a four-part series, N Sundaresha Subramanian looks at social media stars in poll-bound states of Tamil Nadu, West Bengal, Assam and Kerala.