Well sort of.
It seems almost every other day someone asks me if advertising on AdWords helps their natural rankings on Google at all. First here is the official answer:
From the Adwords Blog:
It’s important to know that Google’s advertising programs are entirely independent of the unpaid search results. So being an AdWords advertiser doesn’t affect the inclusion or ranking of your site in the Google search index. Put another way, being an advertiser will neither help nor harm one’s inclusion or ranking.
What about the unofficial answer? Periodically I see speculation in the forums where someone says something along the lines “I dropped AdWords and a week later my ranks disappeared. There must be a link”. I don’t call that evidence.
Personally I have never seen any convincing evidence of a direct link and would be very surprised if anybody ever could prove one. I simply don’t believe there is one.
Having said that though, I do feel that there is a degree of an indirect link that can help a sites natural rankings. This link is no stronger though than the link between advertising on Microsoft AdCenter (or most other forms of advertising) and Google’s natural ranking.
The link is simply that by advertising on AdWords, your site gets seen by more people. The more people that see your site, the more chance there is of someone linking to your site or doing something that can have an impact (usually positive) on your natural rankings.
So the link is weak and its indirect but if being pedantic, I have to disagree with the last sentence in the above statement from AdWords.