The organization has optimized databases which are used in current operations and also used as a part of decision support. What is the next step? Data Warehouses and Data Mining are indispensable and inseparable parts for modern organization. Organizations will create data warehouses in order for them to be used by business executives to take important decisions. And as data volume is very large, and a simple filtration of data is not enough in taking decisions, Data Mining techniques will be called on. What must an organization do to implement a Data Warehouse and a Data Mining? Is this investment profitable (especially in the conditions of economic crisis)? In the followings we will try to answer these questions.