Davinia,

I just finished an AdWords chat session regarding the same thing: ads with no competition appearing at the page bottom, below all organic SERPs. To my utter amazement, the AdWords rep claimed that Google researched and found that - get this - ads placed at the bottom will have a "higher" response due to the "flow" of viewers' browsing. So, my no-competition ads are appearing at the bottom. Not surprisingly, they've received zero clicks in over 150 impressions.

A nearly identical campaign for this client, run exactly one year ago, garnered a 4.4% CTR with the no-competition ads appearing ABOVE the organic SERPs. I tried to get the rep to agree with me that his description of this algo change was counter-intuitive and - based on my results so far - will yield abysmal clickthroughs and profit for Google. He was unmoved.

I also asked him why - if the results of bottom-scraping ads are so good - don't they charge advertisers MORE for the bottom position, rather than the #1 position? He didn't really respond to that.

I finally asked him to ask his supervisor to override the algo and let my ads run at the top of SERPs, as an experiment in performance/profitability. He said that's impossible - "out of our control."

If anyone has any insights regarding this unbelievably bizarre claim that bottom-scraping ads will perform better than those at the top of the page, I'd like to hear them.