I feel like you're almost advocating for a "Google where -only- ads are displayed.

>> At no point would I accept the product choices to be decided by who pays Microsoft more

But in all your examples you're absolutely going to get products which pay MS more. Pizza from the "highest rated place". Rated by whom? Against what criteria? Neutral professional Chriatmas Gift; I mean, paid product placement here we come.

>> But I'm perfectly fine with a neutral chat taking 5-30% cut on the transaction.

So, I sign up to "supply" (but not "advertise") my product for a 30% cut of the proceeds, but you don't expect the engine to push the higher-value ,higher-cut options? The engine should be neutral - regardless if the product is signed up or not? Regardless of the commission?