The purpose of this article is to determine the efficiency of investments in Big Data, conducted by Amazon, Alibaba Group and eBay - three global leaders of e-commerce based on dynamics of their main economic indicators and consumers’ feedback analysis. The authors analyzed the investments in research and development as well as the latest projects related to Big Data. They are mapped to the value that consumers of these companies receive as a result of utilizing Big Data. Consumers’ consent to the companies using Big Data to enhance their customer experience is analyzed. Authors allocated the following as value parameters: relevance of individual (target) advertising, special offers and actions, transitions to sites of e-platforms. The correlation between consumers’ attitude to the use of their personal data through utilization of Big data and the quality of individual offers of the goods they receive from sellers are investigated and evaluated. Recommendations offered on how online retailers can utilize Big Data investments to further its operations.