In the knowledge of business partners (customers, suppliers, sponsors,…) there is a knowledge of a potential so high that can be considered a fundamental strategic resource. Know what the customer thinks of a given product/service helps top management to introduce improvements in the processes and products, such as to differentiate the company from their competitors and gain competitive advantages. Customers to express their opinions use frequently web 2.0 tools (blogs, wikis, blogs, forums, social networking). The value of company is measured by what consumers are available to pay to buy its products. Customers with their preferences decree the success or failure of a company. The customer when writes his reviews on a product/service transmit emotions in the message that he feels first and after purchasing the product. For the enterprise understanding customer emotional needs is vital for predicting and influencing their purchasing behaviour. It is necessary to enrich the strategic enterprise information systems with this customer information that is useful for strategic business planning. In this paper, we describe an algorithm, for processing and polarizing customer opinions, based on emotional indexes to discover the affectivity in textual reviews. In this way we take in consideration the management of external knowledge (Extended Knowledge Management) while the Knowledge Management strategy, generally, aims on the efficient and optimal management of internal enterprise knowledge. [ABSTRACT FROM AUTHOR]