Yeah, but Google does nearly the same thing with search personalization and context sensitive ranking. Almost all personalized information retrieval systems ar

Yeah, but Google does nearly the same thing with search personalization and context sensitive ranking. Almost all personalized information retrieval systems are some variant of this type of recipe since the late 90s no matter what mathematical model they use. Perhaps the problem for Google is that there is strong incentive for the content providers to play a cat and mouse game (aka SEO) with google. Depending on business model, anyone sufficiently popular in this space will probably have similar problems once companies have to either pay for content or revenue share. Github is a situation where people (open source developers) "donated" their code to Microsoft, but most of the world is not that egalitarian.