Wilburforce - 12:22 pm on Nov 1, 2012 (gmt 0)

Because in many cases Amazon is NOT providing the same product-the product description is so spammy it comes up for many search terms.

A good reason. However, my question was meant on an "all else being equal" basis.

This is no longer about ranking. It is about obstruction of trade to small businesses and illegal conduct by a major monopolistic corporations.

A fundamental difficulty in that argument is whether simply failing to return an unpaid listing at or above a certain position could ever amount to obstruction. The FTC may well offer some clarification of what Google's duties are, and may also rule that some filter methods are illegal (although the second point rests on the first: what duties - if any - does Google have to either webmasters or the public at large to return results in a particular order?).