Google Analytics, Quantcast, and Chartbeat are a good start. Google Analytics gives you the ability to slice and dice your visitors. Quantcast gives you demogr

Google Analytics, Quantcast, and Chartbeat are a good start. Google Analytics gives you the ability to slice and dice your visitors. Quantcast gives you demographics. And Chartbeat gives you real-time tracking with historical playback. Between the three of them, you can discern almost any information you'd want to know about your visitors short of business logic tracking.