It's there technology. It rates websites by calculating how many links exist from another sites to this one.
Maybe the word "backsub" isn't right, but that's how they do.
well for one, Yahoo and MSN both used google as their search engine until not too long ago. Google also is a very strange company and does things that don't quite make sense, and they are led by like a panel of lawyers if that tells you anything.
I read a stastistic that google could only search like 5% of the internet, which is funny considering it pulls up millions or billions of hits for regular average searches.
here is MS new search engine, I kind of find it annoying after it loses its humor, which is really quick