In the digital era, Artificial Intelligence (AI) and Big Data-powered marketing analytics are changing business strategies by empowering deeper customer insights and operational efficiency. This study explores the interplay between technological advances and ethical concerns to determine how companies use these marketing analytics tools to attain Return on Investment (ROI) while protecting consumer trust and regulatory compliance. The study focuses on key technological applications, including predictive modelling, natural language processing, and customer segmentation, which have been proven to increase ROI by 20–30%. It also explores data privacy challenges, algorithmic biases, and the integration of ethical frameworks like GDPR and CCPA. The research will follow a mixed-methods approach, with both quantitative data analysis and qualitative industry case studies, to provide businesses with actionable insights on using AI and Big Data ethically and ensure sustainability in marketing practice. Important findings include the dual importance of both technological adoption and responsible data governance on business performance and consumer trust. This study highlights the paramount necessity of transparency, fairness, and accountability by businesses in the ever-evolving digital landscape.