Sentiment Analysis is considered as a critical research technique for collecting and analyzing textual data that is available on social websites. SA is also used as research method that systematically evaluates the consumer opinions in real sense in an efficient and effective manner. Marketing experts can collect rich data on attitudes and opinions about the products and services which help them in taking a relook at features which are positive and negative and use this as feedback system to rectify anything. By identifying the polarity of opinion either positive or negative will help businesses to identify right strategies to make their brands appreciated better by consumers. This review paper focuses on evolution of sentiment analysis, synonyms and why it is used and how research has happened related to how SA could be used in e- commerce. © 2016, Institute of Integrative Omics and Applied Biotechnology. All rights reserved.