keep track of historic events per unique visitor.
like:
- initial search phrase used to find you site
- most recent newsletter / partner / campaign responded to
- goal conversions
- perhaps a few custom fields which an ebusiness can use to identify buyers while an informational website can use it to store the visitor’s specific interest
this kind of information can be very useful for, for instance, segmenting your audience, search phrase / key word performancetricky bit will probably be making sure that the correct record is mapped to the correct visitor