By the introduction of web 2.0 and cheap accessibility of web, many merchant sites are operating and providing space for their users to share their experiences in form of customer reviews. Such reviews contain precious knowledge useful for both customers as well as manufacturers. E-customer accesses these reviews to know opinion expressed by existing users on a product before making purchase decision. Further, such reviews are used by manufactures to know shortcoming in their existing products as well as to know strength of a competitor products for making business plans.