according to http://www.google.com/intl/en/privacy/ads/ http://www.google.com/intl/en/privacy/ads/ the "interest categories" are based on the sites you actually

according to http://www.google.com/intl/en/privacy/ads/ http://www.google.com/intl/en/privacy/ads/ the "interest categories" are based on the sites you actually visit that have doubleclick ads, not from search terms (though there's an obvious correlation between the two, I suppose).