The marketing mix has evolved over time from Borden's original 12 elements in 1965 to McCarthy's widely adopted 4Ps framework of product, price, place, and promotion in 1964. Since then, various researchers have proposed expanding the marketing mix for services and digital marketing. Booms and Bitner added people, physical evidence, and process for services. Lovelock and Goldsmith suggested personnel, physical assets, and procedures. More recently, frameworks have incorporated personalization, partnerships, and customer-focused elements like preference, budget, and relationship permanence. For e-marketing specifically, some incorporate additional dimensions like personalization, privacy, customer service, and community in recognition of digital marketing's unique relational functions.