Any data which poses a challenge for currently existing database technologies is termed as Big Data. This research paper is based on highlighting how retail industry makes use of big data in targeting customers. In today's busy life no one loves to receive unnecessary junk mails or messages. It is because of this that companies want to be crystal clear about each of its customer's interest and his or her pattern of shopping and expenditure. To be precise in knowing the interest of customers, companies needs to regularly mine the data related to each individual customer and gain insight of their shopping habits like which goods customer prefer and buy, customer's budget, customer's likes and dislikes etc. Future of retail is totally dependent on big data analytics as it is capable of separating wheat from the chaff. Retail is adopting data centric technology for boosting sales. Retailers have achieved 73% increase in sales with assistance of Big Data. Retailers are mining customers analytics to increase profits, increase growth and to be in competition, whether it is in-store or on-line. For handling such a huge database of millions of customers, companies make use of powerful framework like Apache Hadoop. Apache Hadoop is one such framework which is capable of handling huge databases via its several components. The retail market has always been interested in finding and analyzing new buying trends in customer's behavior. The central theme of this research paper is to highlight the entire process which is conducted by big retailers in different fields to attract customers and bond healthy relationships with them as satisfied customers are company's life time asset. The paper also elaborates how Apache Hadoop framework handles the enormous databases involved in retail industry with prime concern of increasing revenue growth.