1. Aggregation of User Contributed Content
2. Aggregation of People, Projects, and Programs
3. Build a New Content Discovery Methodology (i.e. Tag Clouds)
4. Creation of Semantic Relationships between Tags
5. More Current and Accurate Information Classification
6. Representing the User Point of View, not the Librarian’s
7. Create a Base of a Corporate Taxonomy and Folksonomy
8. Develops a Core Inventory for Tag Suggestions, Ajax
9. Provides Instant Feedback on Value Add
10. Helps in reviewing the Competition for your Area of Interest
11. Ensures that you use the Tags that Represent the Head of the Long Tail
12. Increases the Number of Connections to your Content; Findability
13. Locate like minded Contributors via Tags
14. Encourages the Remixability of Content by Initial Classification
15. Helps Promote Metadata; Amen

This one was hard and help out there?