This chapter examines the growing role of generative and agentic artificial intelligence (AI) in transforming marketing and sales practices. Drawing on contemporary research, the chapter traces the evolution of AI from rule-based systems and predictive analytics to generative models capable of producing content and agentic systems capable of autonomous decision-making. Generative AI enables scalable content creation, personalized communication, and enhanced forecasting, while agentic AI introduces autonomous marketing systems that dynamically optimize advertising, pricing, and customer engagement strategies. The chapter also discusses real-world industry applications, illustrating how AI-driven systems enhance customer experience, operational efficiency, and revenue performance. In addition, the chapter highlights key ethical and governance considerations, including algorithmic bias, transparency, and data privacy. Overall, the analysis demonstrates how the integration of generative and agentic AI is reshaping marketing strategy, customer engagement, and sales management in increasingly intelligent digital marketplaces.