I wonder if someone was fired on Discover side for having the idea to run a campaign on the Kindle with such a bad ROI. But I am not familiar with the ad business, maybe the efficiency was in line with what could have been expected...
It was a new platform/venue with an company they were spending 30 times a much on advertising. This strikes me as a "nothing ventured, nothing gained" and "none of us realized they were a criminal organization". Unless all advertising venues are roughly this bad (Neilson has a service where they track advertising to allow companies to confirm they're getting what they paid for...) this one effort shouldn't be such a black mark for those on the Discover side, prior to their learning these ugly details.
Well, the efficiency was as low as it was because of an implementation bug on Amazon's side. It didn't work the way it was intended to. If it had, who knows, it might have done well. The campaign certainly makes sense to me in a vacuum.
