The accesslog in the statistics module isn't the most elegant thing.
What it does is, each page view it writes to the database these items:
- Page title
- hostname (IP addess)
- Session id
- Page load time via timer_read
Many of these can be gathered by free external tools such as google analytics. These services often offer custom variable tracking, so a contrib module could add this functionality.
I will work on a patch to strip out the accesslog features from statistics module.