A system and method for providing content to users including a multicast sub-system providing content to multiple users and a unicast sub-system providing content to individual users. The multicast sub-system being operative to push to each of a plurality of user communities, content relating to the...http://www.google.fr/patents/US7945672?utm_source=gb-gplus-shareBrevet US7945672 - Unicast/multicast architecture
