Traditionally, the activities of companies are evaluated based on their financial indicators. However, given the abundance of data currently available, globalization and growing competition, financial indicators fail to present a multifaceted picture of a company. The company's financial statements do not suggest what is responsible for achieving these results and what can influence their change. This lack of information is a limitation in the multifaceted evaluation of the company's results; therefore, ineffective decisions may be made. In order to ensure productivity and a high level of activity monitoring, appropriate indicators are needed to facilitate the decision-making process. Also, in many cases, company personnel cannot directly see how the work they perform contributes to the company's goals, thereby reducing the value their work generates. The above problems can be solved by key performance indicator (KPI- Key Performance Indicators) reports, which also serve to supplement financial information with user information. These indicators systematically organize a large volume of data, which provides a better basis for evaluating current processes and making decisions. In addition, the KPI emphasizes that the goals are achievable. The aim of this paper is to analyze key performance indicators (KPI) in e-business. The purpose is to show how they are managed and what they are used for. The theoretical part explains e-business and KPI- as important metric indicators that measure how efficiently the company achieves its key goals. The paper will show how KPIs are set, measured and used through the analysis of relevant literature, the comparative method and the ASOS company case method. The results show an analysis of ASOS' decline in key metrics in 2023 such as total visitors, active customers, conversion rate and total orders. The data of these key indicators can show the ineffectiveness of marketing campaigns, the ineffectiveness of website design, the increase of competition and the lower visibility of ASOS on the Internet, and the analysis of the results can help the company in successful business because they indicate problems and omissions. The paper shows how the theory is applied in practice and is used for all companies that operate online.