I'm looking for software that can analyze my Apache log files (or some other source) and tell me, from the visitors that actually bought something from my site, some profiling information; like time of their first visit, how long they spend on my website, what the original referral was, etc?
In principle a tool like Awstats provides a lot of information, but I'd like to have it filtered to individuals.
Edit: Instead of Apache log files / using IP addresses, I'm also happy to add something like php code to my site to identify returning visitors.