Measuring performance is a complex task that requires careful consideration of accuracy, precision, and the type of latency being measured. Cloudflare's experience with customer performance escalations has led to the realization that traditional metrics like Time to First Byte (TTFB) may not be the best representation of true web performance. A more nuanced approach is needed, taking into account the number of requests made by a user and the probability distribution of latency across different percentiles. By using percentile-based metrics and visualizations, such as CDF plots and QQ-plots, Cloudflare has gained a deeper understanding of its customers' experiences with latency and can now provide more accurate and actionable insights to improve performance.