The report intends to discuss the application of Tesco’s e-business system which facilitates the data collection of its customers and evaluate its contribution to managerial decision-making. It also analyse the ethical issues that arise from the collection and use of this information. To shop online at Tesco, the individual has to first get itself register with Tesco.com. For registration, the person is required to submit the full name, e-mail address, clubcard number, day time, evening time and mobile telephone number and full home address. Tesco’s system also uses cookies to collect the behavioural information regarding its customers. Non-registered visitors of the site are sent anonymous cookies to keep track of their browsing patterns and build up a demographic profile. E business system has had huge impact on Tesco’s achievement of Customer Relationship Management (CRM). It highly facilitates the managers at Tesco in making strategic, tactical and operational decisions. By monitoring customers’ activities whilst they are shopping on-line, the managers will be able to understand their customers’ needs better and therefore design products and services that match their needs more closely