Many of the lower quality sites Google targeted with its algorithm update rely on Google AdSense ads for revenue. Many low quality sites have been created over the years just to make AdSense money. Obviously Google knows this, but when some of the big sites often labeled as content farms churn out mass content, there is potentially a lot of money to be made for both that content site and for Google. So a question like, "Does your advertising spending with Google influence your position in Google’s natural search?" isn’t exactly unheard of.

In a recent Google Blog post, Matt Cutts wrote: 

One misconception that we’ve seen in the last few weeks is the idea that Google doesn’t take as strong action on spammy content in our index if those sites are serving Google ads. To be crystal clear:

– Buying Google ads does not increase a site’s rankings in Google’s search results.

That’s Google’s "crystal clear" position on the matter. Whether you want to believe it or not is up to you. This will likely be questioned for years to come – never proven or disproved. With eHow still ranking so well in Google, the disbelief of some will no doubt continue. 

Jason Calacanis, who has been in the headlines today due to layoffs at Mahalo, shared some thoughts on Quora about Google search quality and its relationship to AdSense. On whether or not ad spend with Google influences natural search position, Calacanis,  whose site Mahalo was hit hard by the Google algorithm update (hence those layoffs), says, "No way."

He wrote:  "These two sides of the business have a 100 foot chinese wall between them. I know, because over three companies and tens of millions of dollars in google adsense revenue I can tell you that when we had an issue with Google search even *ASKING* the revenue side resulted in a response like ‘you don’t want us to ask Google search quality for help because they will not listen to us or even let us in the building. Church and state in my experience."

"Now, I do think that Google *might* be alerted to the existence of a site via things like google chrome, google analytics and google adsense," he added. "This means that the google spider might crawl your site quicker because of these services, but it doesn’t impact your rank in any way."

He goes on to say that he thinks people get "conspiracy theorist" about it. Like many conspiracy theories, it may not ever go away. 

Google did devalue a lot of sites that use AdSense. 

Another Goolger (in the same Quora thread) poitned to this page as the most basic explanation of what affects a site’s ranking.