All Google needs is an obvious, one-click "spam" button for logged-in users. Clicking should add a site to the user's spam blacklist (which they should be able to review).
They know about what users search for and how those searches overlap and separate users into groups (not to mention all the individual details they have access to). When sites are marked as spam by enough different types of users, those sites can then be manually reviewed and their content blacklisted by Google preventing the same or very similar sites with a different URL from appearing.
Unfortunately, Google makes a lot of money from these ad/spam sites, so they have a perverse incentive to keep allowing them.
All Google needs is an obvious, one-click "spam" button for logged-in users. Clicking should add a site to the user's spam blacklist (which they should be able to review).
They know about what users search for and how those searches overlap and separate users into groups (not to mention all the individual details they have access to). When sites are marked as spam by enough different types of users, those sites can then be manually reviewed and their content blacklisted by Google preventing the same or very similar sites with a different URL from appearing.
Unfortunately, Google makes a lot of money from these ad/spam sites, so they have a perverse incentive to keep allowing them.