But there was a service, AdWhatever, which let users go onto a sub-site of Amazon.com and just casually? recreationally? vote between two ads. You would be presented with two B&W images and click the one you liked more. I don't know that there was any incentive to do this, but I think it was a Bezos idea.

I didn't develop it, but all the routine maintenance tasks that came along (remove this deprecated library, migrate to new hardware, update your pipeline) needed to be done for AdWhatever too. That stupid service lingered for years after it was clear nobody used it, but we had to keep maintaining it until we got the go-ahead to tear it down.