The key to effective traffic analysis is simplicity. You need information about your traffic, links IN and links OUT.
It costs you expenses (time and money) to generate your INcoming traffic. Your OUTgoing traffic generates income... if you "get the click" (on your AdSense ads, affiliate links, order form, etc.).

SBI!'s TrafficCenter makes it easy to monitor your visitors' traffic patterns, especially outgoing/incoming traffic, enabling you to adjust your traffic-building efforts for maximal profit.