Content-targeted ads are served with e-mail. A unique content identifier (“CUID”) is included in the content. A client device passes the CUID to an ad server in a an ad request. The ad server uses the CUID to identify previously registered content for determining content-relevant ads. Current information...http://www.google.co.uk/patents/US7203684?utm_source=gb-gplus-sharePatent US7203684 - Serving content-targeted ADS in e-mail, such as e-mail newsletters
