When "tagging" became all the rage awhile back, many website operators couldn't understand all of the fuss particularly if they had put time into setting up a content classification system they felt was working. But since 'tag clouds' looked so cool, some of them were convinced enough to add the keywords to complement their taxonomies.
However, in a Web 2.0 world, that is simply not enough. Why? Because unless publishers will never be able to anticipate all of the ways that users see and seek out their material. Only by giving users the ability to tag content can publishers be assured that they are not missing key methods for discovering their work.
Fred Wilson notes:
User tagging is vastly superior to self tagging because it is the consumers who are navigating and trying to find the stuff. The way they describe it is the same way they will try to find it. And it's really hard for publishers to figure out all the keywords up front.
What's more, users like to tag (read Del.icio.us) giving yet another reason to add this functionality to a web site. But with this tendency comes a wise word of caution:
Many apps focus on being the new social killer-app when, in general, people don’t have time to worry about what other people are doing, and will only use software that benefits them personally at every step. You could call this selfishness or laziness, but I would call it optimization. For example, we simply don’t have time to tag things for tagging sake. Instead, we might tag things if we think that it will help us in the future, but adding tags to an app does not a solution make.