Reno - 1:56 pm on Sep 23, 2010 (gmt 0)
why would some domains be given this treatment?
I understand tedster's request for hard data, but for the question above, it's not the worst idea to theorize a bit, to see the possibilities.
Could it kick in because some queries bring back a lot of perfectly acceptable results, so this "throttling" is G's way of giving some of those equally-valid sites more visibility (that they otherwise would not get)?
Is it more prevalent with the hottest keyword phrases? or will relatively obscure searches also trigger the same thing with certain domains?
Does it happen at approximately the same frequency to info sites & affiliate sites & commercial sites & social networking (such as blogs & forums), etc (in other words, "across the boards")? or is it more likely to happen, for example, to a site with a strong affiliate aspect and somewhat less original/authoritative content?
Many questions, few answers at this point...