Tribalfusion.com minimum 2000 daily visitors

To be considered for Tribal Fusion's® representation, publishers must have:

- A minimum of 2,000 unique users per day.
- Highly targeted, relevant and regularly updated content.
- Professional site design.
- An active user base.

source:
http://www.tribalfusion.com/SmartPublishers/requirements.html

key: click perimpression

via:
http://me2ultimate.com/get-a-niche/ > 'pay per impression' block