1. A computer-system-implemented method for providing content, the method comprising: using the computer system, loading a document associated with a first domain, wherein the document includes an embedded document associated with a daughter domain, and wherein the embedded document includes an embedded advertisement associated with a granddaughter domain; receiving information in the granddaughter domain indicating that a viewer of the document activated the embedded advertisement; in response to receiving the information, determining if the document supports a cross-domain communication technique; if the document does not support the cross-domain communication technique, determining if the first domain is different than the granddaughter domain; if the first domain is different than the granddaughter domain, invoking, in the granddaughter domain, a series of windows corresponding to different candidate origins of the first domain; communicating access commands associated with the windows from the granddaughter domain to the document associated with the first domain, wherein a given access command includes one of the candidate origins, a content identifier for content associated with the embedded advertisement and a source location of the content; and processing one of the access commands having a candidate origin that is the same as that of the first domain using a cross-domain communication module executing in an environment of the first domain, wherein the processing involves linking to the content at the source location, which is displayed in one of the windows associated with the one of the access commands.
4. The method of claim 1 , wherein the windows include iframes.