WebAdverts is a comprehensive system for maintaining a set of rotating banner ads on your site or for setting up a "banner exchange" between your site and others. WebAdverts keeps track of exposures and click-thrus for each banner, as well as of the average total number of exposures per day. Banners can be weighted to control how often they are displayed, and can automatically be expired from the rotation after a designated number of exposures, click-thrus or days.