This is something Aaron Wall has been trying to expose for the past 3-4 years over at SEOBook.com (why oh why are these SO few comments compared to SEOMoz everytime I visit there? this guy is NEVER afraid to speak the truth), and it's just 1 of many disturbing trends happening. Google's mission is simple: they want you to rely less on organic search and more on Adwords for your traffic.

Nowadays, you can't even see what keywords are driving traffic to your site if users are logged in (50% of queries or so). Plus it's hard to even correlated your SEO efforts with rankings because Google does stuff like drop your rankings randomly so you don't know what works.