Welcome to WebmasterWorld Guest from 188.8.131.52
[edited by: tedster at 5:41 pm (utc) on Feb 1, 2012]
and a handful are actually rolling out today and tomorrow.
At about 11pm CST last night the switch was turned off. Wish I could post a graphic from my server. Then at noon today the switched was turned back on. Seeing scrapers and dup sites winning again and legit sites losing. It will be a temporary issue, but one that recurs almost weekly now.
This may explain my traffic changes today
Maybe some other adsense publishers from your niche got penalized, so thanks to lower number of impressions in system average CPC increased a bit.