A little while ago i thought I would take Google's advice and allow image ads back in (as Incredibill did) In addition to following advice regarding Googles image ads I added ad units, unblocked my competitive ad filter and allowed Certified Third Party Networks.
After a very brief October spike which may or may not be attributable to the (aforementioned actions) everything came crashing down with a vengeance. In my recent experience, CTR, average CPC and overall eCPM have all been affected.
So I am now reviewing and concentrating on the Certified Third Party ads and asking for your feedback regarding positive or negative outcomes you may have experienced.
Do you block or partially block these networks?