Diversity, equity, and inclusion (DEI) are crucial for commercial success, fostering innovation, fresh ideas, and mutual respect. Prioritizing DEI is vital for businesses to connect with a broader customer base. A study examined how effective diversity management influences a brand's diverse customer base and DEI policies. It explored the impact of DEI culture, workforce, evaluation practices, product issue resolution, and diversity partnerships on customers. Multinational entities surveyed, with 176 online HR and marketing experts participating. Likert scales, gauged responses, and structured equation modeling analyzed data. The study found that embedding DEI into company culture, maintaining diverse personnel, monitoring DEI performance, addressing DEI challenges with products, and engaging diverse partners positively affect a varied customer base. The research emphasizes that multicultural team leaders must prioritize diversity management for successful implementation, providing a theoretical and statistical framework for effective DEI policies across diverse clienteles.