From TechWeb: An industry group hoping to reverse the trend toward cookie deletion by consumers plans to begin work next week on a plan to help improve the image of the technology used to track Web activity.
Industry Group Looks To Stem Cookie Deletion

Yeah, according to the story:

The idea for Safecount.org followed research that showed an increasing number of consumers were regularly deleting cookies from their web browsers, which greatly diminishes the advertisers and publishers ability to monitor the effectiveness of online advertising or how visitors are using a particular website.

Here’s an idea…tell the websites who arbitrarily add cookies to your browser that you are tired of their intrusive monitoring, and will use browsers like FireFox which allow you to expire marketing cookies after every session…or simply refuse them from the worst third-party offenders.