Bad on page optimization grade, still displays high in SERP

[ClaytonKendall]

I'm looking at the keyword on page optimization report for my site and I have keywords where my landing page is showing up first on the SERP, but my SEOmoz on-page optimization grade for them is an F. Am I ranking high for these terms because no one is optimized for the terms? They are almost all directed at my home page, does domain authority play a role in me ranking high for them? Thanks for any insight.

[NerdsOnCall]

Hi, there are more factors that play into ranking then on-page optimization. In the 2011 ranking factors, you can see that Page Level Link Metrics and Domain Level Link Authority all play a larger role then on-page keyword usage.

To give you an example, Geek Squad ranks in the first few results for "computer repair" but they score an F for on-page optimization. (imagine our frustration)

Getting high quality links from powerful domains, and getting links with powerful anchor text can account for your situation. I am curious as to why your page isn't optimized for those specific keywords? Did you do this intentionally?