Subscription-based digital services have become a central business model across software, streaming, membership platforms, curated commerce, replenishment services, and digitally mediated retail. Their appeal rests on replacing irregular transactions with continuing customer relationships that generate recurring revenue, richer behavioural data, and stronger possibilities for long-term engagement. Despite this growth, the literature on digital subscriptions remains fragmented. Studies often examine subscription architecture, customer lifetime value, churn prediction, or engagement separately, which limits understanding of how revenue generation, retention management, and value renewal interact as a connected system. The review shows that subscription performance cannot be understood through acquisition growth or churn reduction alone. Sustainable subscription management depends on aligning revenue metrics, customer experience, predictive retention systems, and ongoing value creation across the subscriber lifecycle. The article argues for an integrated view of digital subscription strategy. Future research must connect financial logic with behavioural retention and value renewal, while managers must move beyond reactive churn control toward proactive lifecycle governance.