Fred Wilson writes about Tacoda:
The idea is to build a cooperative network among publishers where the data about what people are interested in can be used to target advertising. If you’ve recently been researching voice over internet services on the Internet, then USA Today can offer you Vonage phone service when you are reading the sports page. If you’ve recently been visiting sites to find a new mortgage, The Tampa Tribune can offer you a better low cost mortgage when you are reading the front page.
The big trick is to do this without violating anyone’s privacy. That is the reason why previous attempts to do this by Doubleclick and Engage failed.
Tacoda built the Audience Match Network with privacy concerns at the forefront. The Audience Match Network doesn’t store any data, it just makes real-time matches to serve targeted ads. No personally indentified information is used in the network. It’s all anonymous. And Tacoda is committed to keeping it that way.