The rapid advancement of digital technologies has fundamentally redefined how brands communicate, compete, and cultivate long-term relationships with consumers. This paper examines the evolution of digital marketing strategies and their influence on consumer engagement and brand loyalty across four major developmental phases. Employing a narrative thematic synthesis methodology, the study systematically reviewed 38 peer-reviewed sources retrieved from four databases—Google Scholar, JSTOR, Scopus, and Business Source Complete—published between 1994 and 2023, with analytical emphasis on contributions from 2015 onwards. The review identifies four major evolutionary stages: the establishment of static online presence (Web 1.0), the emergence of interactive social media platforms (Web 2.0), the shift toward mobile-centric and omnichannel marketing, and the adoption of AI-powered personalization and predictive analytics. The findings indicate that interactivity, content relevance, and emotional storytelling constitute the primary drivers of consumer engagement, enabling brands to develop more meaningful and sustained relationships with their audiences. Furthermore, individualized experiences, consistent communication, and value-oriented digital relationships are increasingly critical determinants of brand loyalty. These strategies present significant challenges, including concerns over data privacy, content oversaturation, and algorithmic dependency. The paper makes three principal contributions: theoretically, it integrates Customer Engagement Theory, Commitment–Trust Theory, ServiceDominant Logic, and Relationship Marketing Theory into a unified analytical framework; methodologically, it provides a structured four-phase periodization of digital marketing evolution; and managerially, it offers actionable strategic insights for brand practitioners navigating the contemporary AI-driven marketing landscape. The paper concludes that digital marketing will continue to evolve toward immersive technologies and ethically informed personalization, with consumer trust and transparency remaining central to long-term brand allegiance.