Links
Read @searchenginelandRead @google blog
What's new?
Google was lately (Jan '11) accused of allowing content farms to gain high page rank. We have their answer now (for US market). This is major change affecting 12% of search results, thus we have an revolution.
This actually is very impressive as Google is one of the biggest corporations in the world. They had a major flow undermining their credibility and they were able to come up with an proper answer in ... 3 weeks? Most medium companies wouldn't even had a plan in such a short term.
Changes
Google noticed that most of today's internet is copy & paste (aka webspam). They found a way to find out where the chain starts (ie. information/signal origin) and rank it waaay higher than copies. Good, wise, simple (to explain at least :).
Impact is on those who mainly copy content and on linking-only sites (without comments and so on). In short: the less home-brewn content, the lower the points in rank.
How that affects content farms
Since content farm is just automated copying of prepared content with little changes, whole farms hopefully get taken down with this change.
This is however a war for really big $money$ and webspammers might come up with something new, like using HBGary's idea of creating and managing whole fake societies (aka Sockpuppet Management Software). That would give them randomized social content, forums full of generated posts and so on. That would be hard to catch, because social activities are very, very hard to measure with math. Also facebook makes real humans' conversation very shallow: