I think they are boosting ranking for Google Aanalytics integrated sites with DoubleClick cookies running. If you remove or change analytics Google tanks your ranking. I ran experiments including google ads for a few months a couple of years ago. They set me up with an account manager who moved me to a new analytics account that added Doubleclick cookies. I've been trying to remove the advertising cookies since then and it's impossible from within the Analytics console. If I plug in a new Analytics account my SEO placement tanks. I feel like it's a racket that gives away my site's user data in exchange for rankings. Help!