13. The computer-readable storage device of claim 12 , wherein associating a respective weight with one or more nodes of the document object model further comprises: increasing a weight associated with a first node of the plurality of nodes if the first node represents one or more document parts that include the search terms.
14. The computer-readable storage device of claim 13 , the operations further comprising: increasing the weight associated with the first node if the first node represents one or more document parts associated with an impression.