...But this is their core search competency and exactly what makes their search so powerful. Page rank is basically distributed wisdom of crowds, aka algorithm of how people behave (build their websites) based on a search term/imbedded link.
This seems like a perfect extension of this. Remember the vision of google: "to organize the world's information and make it universally accessible and useful." Human behavior falls squarely into a large segment of the "world's information."