Building an integration with Mixpanel enhances value for mutual customers by following specific steps to ensure effectiveness and visibility. Obtaining Sandbox access through a free Mixpanel account is crucial for testing, while defining an Integration ID helps with resource allocation and event data source identification. Data can be sent via the Mixpanel HTTP tracking API or supported libraries, with options for EU server connectivity. Integrations should support auto-populating Experiments reports to optimize customer A/B testing experiences and sync schemas to provide data context within Mixpanel's interface. Quality assurance can be conducted using the Events report to ensure functionality, and thorough documentation on the company's website is essential for customer understanding and usage. Finally, submitting the integration to Mixpanel's Integrations Directory maximizes exposure and customer discovery.