Google Analytics

Google Analytics is enormously capable and famously hard to read. Its event-based model rebuilt the navigation around explorations and free-form report builders, trading the old fixed reports for flexibility most users never asked for. Dimensions and metrics get assembled by dragging fields into a grid, and the trend charts and comparison toggles are genuinely good once you've found them. The trouble is everything before that: terminology that overlaps confusingly, settings split between account and property scopes, and a default landing view that buries the one number a marketer actually came for. Date-range and segment controls are strong, but discoverability is weak — the interface assumes an analyst, then ships to everyone. Mastery is real; the on-ramp is brutal.