The sort of methods 'PageRank' uses already existed. It reminds of Apple `inventing` (air quotes) the mp3 player. It didn't, it applied existing technology, re

The sort of methods 'PageRank' uses already existed. It reminds of Apple `inventing` (air quotes) the mp3 player. It didn't, it applied existing technology, refined it and publicized it. They did not invent it but maybe 'inventing' something is only a very small part of making something useful for many people.