Venture Beat: "Targeted advertising usually relies on "cookies" that a Web site places on your browser when you visit it. The cookies can afterwards track which individual pages the visitor accessed. Cookies have a number of limitations, not least their inability to see what a user has done away from that particular website. Technology developed by NebuAd uses a different technique called "deep packet inspection." NebuAd offers its packet inspection software to internet service providers. NebuAd then turns around and provides the traffic information to advertising networks.
Surfers visiting pages with ads from NebuAd-affiliated networks will find the ads more likely to be meaningful to them; a user researching electric cars, for instance, might be less likely to see an ad for an SUV, and more likely to see one for a Prius."
The company can make gobs of money if it just datamined, packaged and sold behavior information it gathers. And AdBlock Plus must have updated its filters, it wouldn't let Firefox render NebuAd's site at all.