Associating source and search keywords with account creation | As a part of the signup process for my online application, I'm thinking of tracking the source and/or search keywords used to get to my site. This would allow me to see what advertising is working and from where with a somewhat finer grain than Google Analytics would.


I assume I could set some kind of cookie with this information when people get to my site, but I'm not sure how I would go about getting it. Is it even possible?


I'm using Rails, but a language-independent solution (or even just pointers to where to find this information) would be appreciated!