> the kind of statistical data mining that even comprehending should make your head hurt.
That's me. I look at an awful lot of data, but on self-reflection I find that after doing that, I tend to "go with my gut" -- some high-level abstraction of what I "feel" I'm seeing. Sort of an "Seemingly-futile Excel analysis until 3:00AM, and no confidence in conclusions or decisions until after a good sleep" kind of thing.
One of the things I "feel" is that the presence of google.com/url?cd=N referrers in the log indicates the activity of this profiling system (or at least its front end). That may be blindingly-obvious to the participants in this thread, but I though it worth a mention.
My highest-ranked, highest-traffic, most-frequently-spidered site is 99.99% informational, so I feel I'm getting a one-sided view of some of the factors being discussed here.
So back on the "data mining" side, I'm wondering if anyone here is seeing anything in their search referrals --the keyphrases most specifically-- that correlates with the behavior that Shaddows terms "exposure patterns" here or with the presumed "Google boxes" or "classification buckets." On sites that offer both informational and marketing content, is there any difference between the google.com/search referral patterns and the google.com/url?cd=N referral patterns? -- Does Google clearly "test" (using the latter referrer type) your marketing or your informational content URLs more?