Interesting NY Times article about Yahoo!. Some key quotes:
"The idea that human judgment can improve a search engine's automatic findings is hardly new. From the dawn of the Web's history - that is, over the last 15 years - companies have invented tools to help users assess the quality and relevance of information, often by relying on others' opinions. Examples include Amazon's user reviews, eBay's feedback ratings and "trusted networks" created on many sites.
What is different is Yahoo's systematic plan to build "community intelligence" into nearly all aspects of its operation - and in turn, to entice users to spend more and more of their time on Yahoo sites, where they can see Yahoo ads. The clearest example, of many I heard about, can be seen at http://myweb2.search.yahoo.com, the beta version of a new search site."
(emphasis mine) Also a couple of great soundbites from Yahoo! staff:
"We're really about getting the average consumer to move their lives online."
"The value of the system is in the aggregate."
The word "system" was mentioned 8 times in the article - not sure if that was the NY Times reporter's particular obsession, or the word was used frequently by the Yahoo! people he interviewed.