I know sales patterns and traffic source/keywords etc. AS above we have seen lots of junk traffic, the problem with trying to analyse SERP's is what I see is not going to be what my customers see! Tghe fact remains, post Instant(& an algo change I am sure) things changed just like May Day. I could see no change in SERPs with May Day either apart from short periods where we disappeared totally.
Anyway, I'll leave this thread until I can pin SERP's to sales patterns ;)