This document discusses extracting insights from data exhaust, or unused data. It provides 10 lessons for doing so: choose a meaningful problem, find relevant data, raw data is better than processed, guide user input, solve easier problems first, create a quick baseline model, test on sample data, use continuous integration, pick the right tools, and prioritize developer productivity. As a case study, it analyzes skills data from attendees of the Strata conference to understand the audience and identify skills clusters. Visualization tools like Gephi are used to analyze similarities between attendees based on their skill vectors.