8. The system of claim 7 , wherein the at least one characteristic is not included in the search query.
7. A system for delivering content from a corpus of data including a plurality of items, comprising: means for receiving a search query, searching the corpus of data, and generating a search query result set that includes one or more items from the corpus of data; means for identifying a rule having a trigger that specifies at least one characteristic corresponding to a plurality of items in a corpus of data and defines a content presentation action to be performed responsively to the trigger; means for determining a percentage of items in the search query result set that correspond to said at least one characteristic and comparing the determined percentage of items to a predetermined threshold percentage; and means for presenting content in accordance with the content specification action when the determined percentage of items exceeds the threshold percentage.