This chapter offers a critical and theory-based analysis of the value and challenges of adopting generative artificial intelligence (GenAI) in marketing by business organizations. Drawing on the general-purpose technology (GPT) view and the diffusion of innovation framework, the chapter explains how GenAI evolves from invention to adoption and then diffusion. The latter is the most important stage, because the true impact of GPTs materializes only when technological advances are transformed into practical products and applications that are diffused throughout the economy. GenAI creates value for marketing in four main domains, including branding and communication, customer experience and service, innovation and strategic analysis, and marketing operations. In each domain, GenAI offers speed, scale, lower costs, and new forms of creation, insight generation, and personalization. Yet these gains come with risks such as homogenized creative output, cultural mistakes, privacy concerns, biased data, and weak reliability. A central contribution of the chapter is the examination of the barriers that limit adoption. These include technical problems like hallucinations, trust and transparency issues, unresolved copyright and IP, or Intellectual Property challenges, ethical risks in the absence of clear regulation, and economic or organizational obstacles such as low return on investment and strategic misalignment. As a result, GenAI tools often produce competitive parity rather than sustainable advantage. The conclusion is that effective adoption requires human-AI collaboration supported by strong governance frameworks. Long-term value in marketing emerges when GenAI augments, rather than replaces, human judgment and creativity.