Google did some kind of AdWords upgrade Friday night (and adwords was down until about 1 AM EST). Has anyone noticed any significant changes? In some of my major campaigns impressions have dropped to nearly 10% (EG: from 10,000 impressions to 1,000 impressions) Anyone else notice any adwords changes?
No, from my side at least I just checked 11 different clients account that I'm running and all have similar stats from before the maintenance. Normally these upgrades do not affect the front end side - they are related to a server migration or a database version upgrade that requires to stop the front end. There are a lot of upgrades that they run and do not need to stop the front end and you do not notice also.
I think I figured out the reason why the big changed. I was bumped down from a 3.5 ish position to a 4.5ish position. Considering that the larger ad units only hold 4 ads at a time my ad would not be displayed as often.