Found a good post on the difference between commerical sites and research sites in terms of how they rank in search engines.

For a content based website it takes no time at all to do keyword research using some of the keyword research tools on the market, and then quickly create pages around common customer questions, concerns and buying points. If few sites cover those topics with specific pages then it is low hanging fruit waiting to be claimed. I think it was Peter D who said the key to making money on search was to dig where other people were not digging.

This information came from SeoBook.com and I agree with it as I’ve noticed the same things, but more in Yahoo than Google.   I’ve seen Yahoo’s behavior more skewed to the commercial sites while Google is more skewed to the research and academic in terms of rankings.  But Google did push people, indirectly, to use AdWords if they are really a commercial site - in order to save the best organic results for more research oriented sites.   As far as MSN, I’m not sure where they are in the scale of commercial vs. research, but I’ve already written about Yahoo Mindset a couple of days ago in this blog.