alephh - 10:25 am on May 8, 2010 (gmt 0)
ken_b: there is no way of knowing if the drop in CTR is at all related to Interest Based Ads.
So, first reports of CTR collapse emerge in Feb 2010, AND AT THE SAME TIME, Google states in their Inside Adsense blog that they are expanding the time interest-based-ads stay active, and at the same time visitors start to complain about seeing unrelated ads, and I start to see the same ads following me, and webmasters start to see the same ads following them and unrelated ads.
Several webmasters state that: Traffic is normal, from the same sources, with the same keywords, advertisers in their niches report no changes in their campaigns, no changes in sites, etc...
Yeah, right, we have no way of knowing what just happened, because in real life there is no such thing as causality. Clearly some unexplainable miraculous religious force must be at work here LOL
Until I see a better, more logical, theory about the CTR collapse - which in my case is not balanced out by the increase in EPC - I'm going with the IBA theory, which nicely explains most of the things.