Social tagging is a popular approach to organizing and finding digital content — such as Web pages, videos, and photos — on the Web. Useful on a personal level, social tagging can also benefit enterprises that currently use more formal methods like taxonomies to organize information. Categorizing information with tags can reveal patterns, clusters, and relationships that prompt further knowledge exchange and interaction among people. Social tagging is one important piece of the unstructured information puzzle, but it's not a substitute for formal classification.