Re: All fee paid responses?
"If you get no responses from a search other than those for which a sponsor has paid ..." the search engine is worth roughly the same as Foundem. That is why Google and other general purpose search engines return links for which nobody has paid them do, in fact, return a great many such links. Those unpaid links attract users who can be shown the ads and other paid links.
The question was not whether it was in Google's interest to return links to sites that had not paid for that, but why they would reasonably be required to do so - what legal theory would support such a requirement.
The question of why to use Google rather than Amazon to shop for something is, in fact, a vexing one for Google. I rarely do so, having found Amazon or eBay to be generally much more efficient for the purpose. That attitude, if it becomes widespread, eventually will degrade the price that Google, other search engines, and possibly Facebook, can command from vendors for the ads they sell.