We use third-party advertising companies to serve ads when you visit this website. These companies may use information (not including your name, address, email address, or telephone number) about your visits to this and other websites in order to provide advertisements about goods and services of interest to you. If you would like more information about this practice and to know your choices about not having this information used by these companies, visit here: http://www.google.com/privacy_ads.html
Here’s more information on opting out:
As discussed before, there are networks of companies planting cookies on your machine and tracking behavior across websites. That means you'll see an ad on one site based on what you did on another.
You can opt out for free. Here's the not very well promoted link.
You'll see a list of which members of the NAI are already placing a cookie on your machine and you can get rid or some or all of them.
—Seth Godin