Whitey - 2:39 am on Oct 9, 2012 (gmt 0)
I think these slight drops were due to a devaluation of low-quaility backlinks.
@aristotle - why not other factors involving onsite quality?
Also, when someone says they went up a slot or down a slot, how can anyone be sure of what Google is presenting to users, where and why. There are so many factors that ranking No1, or No3 etc is mostly a redundant expression for many webmasters. It's far more complex these days.
And, my view is that exact diagnosis is getting further blurred with all these algo tweaks.
The bottom line is all SEO's should know what the centralising factors are for manipulating the SERP's. If you strip this back to basic guidelines, and ask yourself how would my site rank if i did nothing but rely on good original content and design with good architecture, plus maybe a single authority link, you get closer to the nub of all reasons.
One can build back from there in modern day SERP's. With quite legitimate improvements.
Google has been moving strongly away from game ranking twists for sometime - and I'm not saying you are one, but many participants in discussions are playing around with things they can never control, or deeds they did in the past which cannot be undone.
That's a part of the reason brands, i believe, are surviving, as they've been given an exemption, for now. Just look at what they've been up to - true some have deep pockets to fix previous mistakes and we have seen some "examples" made out of brand offenders - but not often.