NY Times online has published an interesting dialogue on this topic between a couple of googlexperts.  Goto:   http://roomfordebate.blogs.nytimes.com/2009/12/02/where-google-goes-from-here-part-1/

According to one of them:

Google knows that as good as its search engine and Bing are, both are inefficient. They produce a blizzard of too many answers.

A potentially more efficient threat will come from a vertical search, which social networks like Facebook and Twitter might provide. Imagine you want to buy a camera. Would you rather have the advice of 20 friends whom you know and trust and who share their experience with cameras, or 20,000 or so links from a Google search?

Well, in my very limited experience here, for this blog, most of the page views originated from Facebook.  I suspect this is because the blog is pubilicized through Facebook and Twitter, and the topics are of interest only to my plugged-in friends (whom I thank for their attention and comments).  So, there is a vertical aspect here too, echoing the googlexpert.

Among the statistics that the WordPress platform provide to me, are keywords that brought visitors from the world-at-large to here.  There are very few so far, but it will be interesting to see what keywords in people’s search results lead them to this blog.