Google Adwords and SEO : no relation
Buying AdWords will not cause algorithmic search rankings to rise. The answer is clear and it comes from Matt Cutts.
“It may seem odd for a search engine to speak about the integrity of its results. But like a news organization, we believe we have an obligation to present information as objectively as possible. That’s why we don’t bias our search results based on what people are willing to pay.”
But we can affirm that buying sponsored links via Adwords will clearly be good for your SEO because the site will acquire more reputation, and the brand will be globally more visible, and indirectly, more visitors will come from both adwords links and via keywords as referrals.