Big data has found its application and use in every sector which requires mining of enormous data to extract fruitful information and results. The retail sector too is not an exception anymore. The big giants like Walmart, Amazon, Coca-Cola, and Netflix made use of big data analytics to boost their revenue growth. The biggest asset of retail companies is data gathered by them referring to customer's behavior, buying patterns, likes, and dislikes. 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. It makes use of Map Reduce technology. The research paper is intended to discuss different parameters which the retail companies need to focus on to know their customers better. The paper discusses the concepts and strategies which would be preferably followed and should be known to the retailers to target their customers like when and where to approach them.