A waitlist serves as a potent tool for validating market demand for a SaaS product by allowing potential users to express interest through email registration, which helps gauge the feasibility of a concept before significant investment. Integrating a waitlist with communication tools like newsletters fosters direct engagement with future customers, enabling the dissemination of product updates and feedback solicitation. The Clerk platform simplifies this process by offering a waitlist component that can be easily incorporated into applications, facilitating user management with features like sign-in, sign-up, and email capture. Clerk's integration with Loops enhances audience management by automating the addition of user emails to mailing lists through webhooks, providing a streamlined method to maintain updated user information. The article illustrates the integration process using Next.js, although the component is compatible with various SDKs, ensuring a versatile approach to building a responsive waitlist and effectively gauging user interest in a SaaS offering.