This is bullshit the search engines want you to believe. It's trivial to detect sites that "defeat" the algorithm; you simply detect their incentives (ads/affiliate links) instead.
Problem is that no mainstream search engine will do it because they happen to also be in the ad business and wouldn't want to reduce their own revenue stream.
Problem is that no mainstream search engine will do it because they happen to also be in the ad business and wouldn't want to reduce their own revenue stream.