Amazon Case Study: Detail Pages

In this lesson, we apply everything we've learned about input metrics by walking through a real-world case from Amazon—how we evolved our selection metric to better align with customer needs. This story illustrates the complexity, rigor, and iteration involved in making metrics truly actionable and impactful.

Key Takeaways:

• We started by identifying strategic input metrics: Inspired by Amazon’s growth flywheel, we identified controllable levers—like low prices, broad selection, and fast delivery—that directly improved the customer experience and fueled long-term growth.
• We didn’t wait for perfect metrics to begin: We initially used simple metrics like the number of product detail pages to represent selection, even if they were imperfect. Early measurement got teams moving in the right direction.
• We learned through missteps: Our first metric for selection encouraged teams to add lots of SKUs—regardless of demand. Sales didn’t grow, and excess inventory piled up. This forced us to iterate.
• We refined our metric to reflect actual customer experience: Over time, we evolved to more nuanced metrics like detail page views for in-stock items, and ultimately to Demand-Weighted Coverage FastTrack In-Stock Percentage (DWC FT %)—a metric that captured whether customers could find, want, and get an item quickly.
• We aligned goals with customer value: Category managers were now measured by how well their products met real customer demand and delivery expectations—not just raw catalog size.
• We replaced estimates with precise real-time measurements: When anecdotes didn’t match our metric outcomes, we realized the problem wasn’t in customer feedback—it was in how we were measuring. We moved from snapshot-based approximations to real-time software tracking, which required serious engineering investment.
• We treated metric-building as an ongoing process: Measurement accuracy improved over years of trial and error, and nearly every customer-facing metric eventually transitioned from rough proxies to live calculations.

To dive deeper into Input Metrics Mastery and learn more from Bill and Colin, follow these links:

• Take the full course at their website: https://workingbackwards.com/

• Buy the book: https://www.amazon.com/Working-Backwards-Insights-Stories-Secrets/dp/1250267595

• Bill's LinkedIn: https://www.linkedin.com/in/bill-carr/

• Colin's LinkedIn: https://www.linkedin.com/in/colinbryar/