For my reference, this is a nice categorization of filters for content in Long Tails as expressed by Chris Anderson on his book The Long Tail
Pre-Filters (Old School Business Models based on Top 10s, Best Sellers)
- Editors
- Record Label Scouts
- Studio Executives
- Department store buyers
- Marketers
- Advertisers
vs
Post-Filters
- Blogs
- Playlists
- Reviews
- Customers
- Recommendations
- Consumers