29. A method comprising: receiving a request from a source to access content of a target Web domain, the request being addressed to a domain address of the target Web domain; retrieving historical relevance data associated with at least one previous request from another source to the target Web domain from a database; identifying at least one interest keyword that is determined to be relevant to the request based on a combination of the domain address of the target Web domain and the historical relevance data, the historical relevance data including one or more context factors collected from the at least one previous request to the target Web domain; transmitting the at least one interest keyword to a server that serves Web content associated with the interest keyword to the source, responsive to the request; and redirecting the source to access advertising content defined by the at least one interest keyword, responsive to the request.
29. A method comprising: receiving a request from a source to access content of a target Web domain, the request being addressed to a domain address of the target Web domain; retrieving historical relevance data associated with at least one previous request from another source to the target Web domain from a database; identifying at least one interest keyword that is determined to be relevant to the request based on a combination of the domain address of the target Web domain and the historical relevance data, the historical relevance data including one or more context factors collected from the at least one previous request to the target Web domain; transmitting the at least one interest keyword to a server that serves Web content associated with the interest keyword to the source, responsive to the request; and redirecting the source to access advertising content defined by the at least one interest keyword, responsive to the request. 31. The method of claim 29 wherein the transmitting operation comprises: transmitting the at least one interest keyword to a document server that serves the source with document that is determined to be relevant to the at least one interest keyword.