Thanks for bringing up this point - I agree Eric - competitive positioning can help you determine value that you bring to the table that your competitors dont.  I'm all for it.  Neilsen does some reports that provide awareness, likelihood to recommend, sentiment and other insightsfor your site/brand and your competitors. You can also pull some of that type of insight out of social listening platforms like NetBase, SM2, Radian6, Dow Jones, Nielsen, and so many others.  I've even done some hacked compeitove sentiment comprisons before using Search: searching for [brand or feature] + "like", "love", hate", "wish" etc. 
Search engines use complex mathematical algorithms to interpret which websites a user seeks. In this diagram, if each bubble represents a website, programs sometimes called spiders examine which sites link to which other sites, with arrows representing these links. Websites getting more inbound links, or stronger links, are presumed to be more important and what the user is searching for. In this example, since website B is the recipient of numerous inbound links, it ranks more highly in a web search. And the links "carry through", such that website C, even though it only has one inbound link, has an inbound link from a highly popular site (B) while site E does not. Note: Percentages are rounded.
Nice work Laura! This is going to be a great series. I'm working my way through SEOmoz's Advanced SEO Training Series (videos) Vol. 1 & 2 to build upon the advice and guidance that you and your team provided to me during my time at Yahoo!. Now many others will benefit from your knowledge, experience and passion for SEO strategy and tactics. Best wishes for great success in your new role.