The subject of this paper is the research and analysis of the application of artificial intelligence in modern business, with a special focus on its influence in marketing activities, especially within the telecommunications industry. The paper deals with defining basic terms and concepts related to AI, reviewing key events and discoveries that shaped its development, and researching specific applications of AI in marketing, including personalization of content, use of chatbots, virtual assistants and smart optimization. Special attention is devoted to the analysis of the use of AI in the marketing strategies of Hrvatski Telekom and A1 to the identification of advantages and disadvantages of this technology through case studies. The main goal of this paper is to investigate and analyze the role and impact of AI in modern business, with special emphasis on its application in marketing activities within the telecommunications industry. The work seeks to understand how AI technologies, such as content personalization, chatbots, virtual assistants and smart optimization, can improve marketing processes, increase efficiency and user satisfaction, and at the same time identify challenges and ethical issues related to their use. Through the case studies of A1 and Hrvatski Telekom, telecommunications companies, the goal is to provide concrete insights into the advantages and disadvantages of applying AI in business. The results of the work show that the application AI in marketing significantly contributes to increasing the efficiency of business processes, improving the user experience, and optimizing marketing activities in telecommunications companies. In particular, the use of AI in content personalization enables better targeting and user engagement, while chatbots and virtual assistants improve customer support and reduce operational costs. Smart optimization of marketing campaigns leads to better return on investment (ROI) through precise targeting and real-time adjustments. Case studies show that AI technologies not only increase the effectiveness of marketing strategies, but also help build user loyalty. However, the results also highlight challenges, such as ethical issues and the need for continuous monitoring and adaptation of algorithms to avoid potential biases and ensure transparency in the use of AI.