The rise of behavioral targeting signals a pivotal shift in how digital platforms understand and influence human decision-making. By capturing users’ digital footprints, ranging from clicks and scrolls to location and browsing habits, businesses and governments increasingly rely on data-driven systems to personalize experiences, optimize services, and shape consumer behavior. This case study introduces the core mechanisms of behavioral tracking, explaining how cookies, device sensors, and algorithmic models work together to build dynamic user profiles. It further explores the strategic uses of this data in marketing, product design, and public policy, while also surfacing the ethical dilemmas around consent, transparency, and surveillance. Framed through everyday interactions and platform decisions, the case invites critical analysis of the trade-offs between personalization and privacy, making it an essential resource for understanding technology’s role in shaping behavior in the digital age.