The Inside AdWords blog announced a new CPA bidding product yesterday called Conversion Optimizer. The tool is intended to "help you meet your ROI objectives by automatically managing your bids according to a maximum CPA goal. By automating the bidding process, this feature helps you minimize your conversion costs while saving you time."
Forum reaction is mixed. Since Conversion Optimizer is requires a minimum of 300 conversions in 30 days, many advertisers cannot try it out.
One who, did, however, is dissatisfied with the tool. Apparently, it's not easy for him to restore his bids as they were before:
I have changed my keyword bids using conversion optimizer tool but iam not satisfied with that tool ,so i would like to know how to insert previous bids for the keywords as they were before.
Yet are just looking forward to seeing how this feature will work on the content network versus the search network.
I agree that PPA sounds much easier on the content network, I'd be interested to see how this could improve the performance on the Google/search network though.
It will take some time before that is known.
If you're interested in giving it a try, Barry has more information at Search Engine Land.