4. The method of claim 1 wherein the automatically determining the set of source portions further comprises determining the set of source portions based at least in part on one or more user specific attributes and one or more other attributes.
4. The method of claim 1 wherein the automatically determining the set of source portions further comprises determining the set of source portions based at least in part on one or more user specific attributes and one or more other attributes. 5. The method of claim 4 wherein at least one of the one or more other attributes is at least one of an aggregate usage history associated with multiple users, an agreement with a third-party advertisement provider, a news item, and a weather report.