Simple? Or simplistic? SEO forums, blogs, and articles are filled with classic examples of superstitious thinking based on just such logic. "I just added AdSense and my site went from PR0 to PR3!" "I just added AdSense and my site went from page 1 on Google to nowhere to be found!" "I just redesigned my site to make it W3C validated and my PR increased!" ...and a thousand other examples you could find by a quick scan of any webmasters forum. Correlation? or coincidence? Either way it does not compute to cause and effect.