The pains and gains method is a customer needs-based approach to product development and marketing that involves identifying the problems or "pains" customers face and how a product or service can solve them (gain creators) or improve their lives (pain relievers). To effectively apply this method, businesses must understand their target audience's needs, behaviors, and preferences through research and empathy mapping. By matching customer pains with product benefits using a value map, companies can create products that address specific customer needs and provide value to customers. The approach also involves considering jobs-to-be-done, which are the tasks customers need to accomplish, and continuously updating customer data to ensure the product remains relevant and meets evolving customer needs.