mhansen - 6:35 pm on Sep 5, 2011 (gmt 0)

Well, it's a holiday weekend in the US and many times Google has used such periods for roll out some of their bigger algo changes. I've got an eye peeled, but so far I'm not noticing anything very disruptive. Has anyone else spotted anything?

On a small group of 1-3 word phrases we track for a site we care for... We noticed a dip in referrals at the beginning of holiday weekend, and looking at SERPS, they are dominated by MFA and Thin Affiliate type sites with large backlink numbers and exact phrase anchors. (a large volume of irrelevant article directory backlinks, with anchor text matching the query)

Other times we have seen this same trend in the last 12-16 months it's been after a lot of Googlebot activity as well. Low and behold, we also saw a high volume of Gbot activity on Aug 30/31, which trailed off on Sept 1.

Aug 30/31 - Peak GBot
Aug 31 / Sept 1 - Gbot activity trailing off
Sept 1 - Current, Spam and MFA dominating top serps. (Almost Every one of the top 10 results has adsense above fold)

If the trend continues as it has for previous times we spotted it, Goog will weed out the MFA in 5-7 days after the gbot activity.