help choosing weblog analyzer

I need a recommendation for choosing website log analyzer, which would allow to track: 1. wich ad program traffic comes from, 2. how much time visitor stays on site, 3. how many human/robot generated clicks web site receives. The analyzer should be downloaded and installed easily (maximum change couple directories), and would not require other programs, drivers, extensions, except Windows OS. Analyzer should be freeware/shareware, $50 or less. There are many log analyzers exist, but I do not have time testing them. Examlpe of log file attached. PS. To clarify the problem: I have one referrer, which generates a lot of robot-driven traffic. In log you can see single page downloaded by some IP, without images, frames, and robot-user quits the site. Basically I need a tool to select good advertisers from bad ones. ## Deliverables Link to installation, not nessessarily your program. ## Platform Windows 2K