7. The method of claim 1 , wherein identifying the authoritative sources associated with query topic comprises: accessing an authority index comprising entries, each of the entries comprising source data indicating a source, topic data indicating a topic, and authority data indicating an authority associated with the source and the topic; searching the authority index for entries associated with the query topic, each of the entries comprising one of the promoted results; obtaining a plurality of promoted results; and ranking the plurality of promoted results and the search result based upon a contribution dimension associated with the promoted results.
7. The method of claim 1 , wherein identifying the authoritative sources associated with query topic comprises: accessing an authority index comprising entries, each of the entries comprising source data indicating a source, topic data indicating a topic, and authority data indicating an authority associated with the source and the topic; searching the authority index for entries associated with the query topic, each of the entries comprising one of the promoted results; obtaining a plurality of promoted results; and ranking the plurality of promoted results and the search result based upon a contribution dimension associated with the promoted results. 8. The method of claim 7 , wherein each of the entries further comprises time data indicating a time associated with the entry, and wherein ranking the plurality of promoted results and the search result comprises ranking the plurality of promoted results and the search result based upon the time data.