Product walkthroughs are interactive and dynamic product experiences that help users understand the value, taxonomy, and functionality of a product. They can be used to retain new users, improve feature adoption among existing users, and ultimately increase retention rates. To build effective product walkthroughs, consider three key factors: The GOAL (identifying Magic Numbers and "Aha!" moments), The CONTENT (creating engaging and relevant content), and The TARGETING (defining user segments for personalized experiences). Test your walkthroughs through internal testing, serial testing tours, and A/B testing to ensure their effectiveness.