I'm seeing a confluence of events that suggests we may have entered another Traffic Shaping
[webmasterworld.com] period, where Google is again measuring user engagement and behavior over a range of varying results, and is possibly throttling traffic to keep data normalized for comparison purposes.
From patterns I've observed in earlier tests Google has run, I'm thinking that Google has evaluated previous Panda results, made heuristic changes in the algorithm, and is now running another "calibration test" to further check user behavior in response to changes.
I suspect that there will be a return for some of what we have called "zombie" traffic.... January 26 2011 Change - Back to "Zombie Traffic" http://www.webmasterworld.com/google/4258897.htm
In that thread I commented....
...almost every new Google search feature I've been seeing seems to be built for disambiguation, including (but not limited to) the returning of general terms in localized serps. Instant and Instant previews, eg, are in a way an extension of Suggest... and a different angle on the choices.
You can also see variations in Suggest that aren't geographic, but which are cyclic....
Over the past several days, I've been seeing changes to various Google search refinements, suggesting that Google may now be running tests for different queries and for a slightly adjusted algo.
Sitelinks and mini-sitelinks have recently changed noticeably. Pages that I assumed would produce low user satisfaction are in fact dropping out.
Multiple results from the same domain for some queries are now being returned for longer queries, almost as if they're now checking user satisfaction on long tail.
And, as many have reported, serps have again been jumping around rapidly, yo-yo fashion.
Instant Auto-complete suggestions that I watch made a big cyclic change roughly a day or two ago.
Additionally, new genre labels introduced in US Google News results [webmasterworld.com
...] suggest to me that Google may have gotten heuristics for document level classifiers to the point where they're testing them live, at least in a limited fashion on News, and that the timing of their introduction might be meshing in with system-wide tests.
For reference on how Google might be monitoring some of this, for those who haven't followed, check this thread.... Panda Metric : Google Usage of User Engagement Metrics http://www.webmasterworld.com/google/4302140.htm
I'm wondering how others who have followed the above-referenced discussions are seeing how these ongoing pieces of the puzzle are fitting together. This isn't to replace the monthly serps thread, and... please... it isn't a thread to complain about Google or your traffic.