Regarding whether there is any way to tell how someone found your item (in what category they were browsing, or what keywords they were using):
Some of that can be found in Sales Reports for your Ebay Store, but the information is quite limited, and applies only to store listings and searches from within your store.
If you -REALLY- want some useful information on your listings (ip address, geographic lookups, search terms, arrival page, what page you were on in their search, whether they bookmarked you, whether they emailed your link to a friend, whether they chose to "View Seller's Other Items", whether they looked at a cross promotion, whether they bid, bought, etc, and TONS of other statistical information) - then you need to go to sellathon dot com and take a look at their ViewTracker product. I used the free trial for about 4 days before I signed up for real. It's amazing how helpful it is, and even more amazing the kind of intel they give you (ie, how many other items a person who "Watches" your item is watching too - even how LONG someone spent looking at your listing). Mildly frightening when you think about being the buyer in that scenario..
I can't recommend it highly enough.
-Kim