Count me if you can!

Assessing actual audiences has always been a tricky task. "Until the new technologies will make it possible to literally count eyeballs," everybody thought. Apparently such new estimates are even more controversial: The NYT reported on this in late 2007 (Click here). In 2009, the controversy still goes strong (Read here).

Behavioral Targeting

If you visited those websites in the past few days chances are that you are interested in their content. So the ads showed now on this website depend on the content of the websites you visited yesterday. This is behavioral targeting. The economist has two nice articles here (Watching while you surf) and here (Behavioral Targeting) on this technique.