A “virtual” directory contained in URLs indicates a CGI (Common Gateway Interface) script is in use. A sure tip-off to the spider that your page is dynamic.
Click-down Ad or Click-within Ad
An ad that allows the user to stay on the same web page, while viewing requested advertising content. Click-downs display another file on the user’s screen, normally below or above the initial ad.
Click-withins allow the user to drill down for more information within the ad.