Like many here I'm a huge fan of Neal Stephenson. A lot of people around weren't big fans of Anathem. I actually really liked it.
One of the ideas that came up in that book was the Reticulum (Internet) was populated by "botnet ecologies" that subtly manipulated facts, streams and the like such that filtering this out became another industry (of course).
I've seen the idea that this lies in our future raised here and it seems to get mocked. I think the idea has a lot of merit.
This makes sense. For me, the main problem of Google is trying to retrieve a treasure out of garbage. While the Internet has a lot of good information, much (most) of it is incorrect -- sometimes on purpose as you suggest. I would be much more interested in a learning system that is able to retrieve information from authoritative sources such as books, for example.
And of course authors and publishers will try to game this. Spam is an AI-complete problem, you'll need a system groking human values and making judgement calls to filter out spam perfectly.
spammers will be populating the web with "facts" that suit themselves.