What are you using to fetch the pages? Something like CasperJS/PhantomJS? If the banners are images or iframes from an external domain you should be able to tra

What are you using to fetch the pages? Something like CasperJS/PhantomJS? If the banners are images or iframes from an external domain you should be able to traverse the DOM and locate them this way. You would have to have a list of ad providers domains to look for and you might miss some.