Implicit collaborative filtering refers to a method of implicit ratings of content. A few common measures of implicit ratings are links to a website or the number of visitors a web site gets. The more links a website gets means that people all over the web think that the website is a good one. If many people are visiting a website then the website is obviously interesting to those people.

Why doesn't eveything2 implement something like this? Thus linked to nodes would be rated as reputable since people are making the effort to link to them. Also nodes that many people visit or edit should also be signified in some way.

See also:
explicit collaborative filtering
collaborative filtering
displaying link quality