Metadata, tagging and folksonomies are hot topics in the blogosphere these days, and with good reason. They truly add value, it will be interesting to see how marketeers will (try to) exploit this.
"In a broad folksonomy, Vander Wal continued, there is the benefit of the network effect and the power curve because so many people are involved. An example is the website of contemporary design magazine Moco Loco, to which 166 Delicious users had applied the tag "design." But 44 users had also assigned the URL the tag "architecture," 28 "art," 15 "furniture" and so on. That means that because so many people applied so many different tags to Moco Loco's site, it could be located in a number of different ways."