flatfile - 3:03 pm on Nov 23, 2012 (gmt 0)

I find it funny that just before Black Friday there is always a massive serp shakeup.

Not trying to claim that Google is innocent here, but I bet that there is a massive change in the link graph during this period. I run a service that involves crawling some parts of the web, and I always notice changes in linking patterns before certain events.