hunderdown - 11:17 pm on Jun 25, 2006 (gmt 0)

2) Unless Google are the shopping cart system, there is no way to verify the volume of sales. Merchants (as a whole) will invariably seek to corrupt the tracking of the system.

I may have missed something, because that point has been confidently made by several people, but I just don't think it need be a serious problem.

I don't see why the only pressure on merchants will be to under-report conversions. As I understand AdWords, an advertiser whose ads are not performing as well as the competiion, based on bid x conversions, risks them ranking lower in the "auction" system for placement in ad blocks, or even having a campaign paused for poor performance.

That's a feature of the current system that keeps merchants honest for smart pricing purposes. Why wouldn't that feature apply to CPA advertising too, and thus help to keep merchants honest?