APIs, pivotal to the digital world, can be monetized through various strategies such as pay-per-use, subscription, freemium, and revenue-sharing models, transforming them into significant revenue sources. This shift reflects how developers and businesses now prefer targeted solutions over monolithic software, driving the demand for specialized API services. Monetizing APIs involves understanding their value to the end user and crafting incentives for developers, crucial for the success of any API business model. Effective strategies range from usage-based billing, like prepaid and post-paid, to packaging options, such as tiered pricing and pay-as-you-go models. Expanding API usage involves making APIs self-service, facilitating easy integration, and leveraging product-led growth while maintaining robust communication to manage API evolution and customer expectations. Key performance indicators like adoption, engagement, and retention metrics help track monetization success, and managing API deprecation with clear communication and migration paths ensures long-term stability and trust.