Abstract:
Third-party advertising and tracking (A&T) are pervasive across the web, yet user exposure varies significantly with browser choice, browsing location, and hosting jurisdiction. We systematically study how these three factors shape tracking by conducting synchronized crawls of 743 popular websites from 8 geographic vantage points using 4 browsers and 2 consent states. Our analysis reveals that browser choice, user location, and hosting jurisdiction each shape tracking exposure in distinct ways.