14. A method comprising: selecting a document that is pertinent to a topic based on searching, using a key phrase, a plurality of documents; identifying an identifier of a party to a transaction being referenced in the document; identifying the transaction conducted by the party to the transaction based on the document, the identifier of the party to the transaction being associated with the topic; determining a rating of the transaction conducted by the party to the transaction based on the document, the determining of the rating of the transaction conducted by the party to the transaction including identifying, from a plurality of polarity words included in the document, a dominant polarity word based on a syntactic distance between the dominant polarity word and the topic in a syntactic tree, the dominant polarity word having a dominant polarity impact on the rating of the transaction conducted by the party to the transaction; and determining, using at least one computer processor, a sentiment of the document based on the transaction conducted by the party to the transaction associated with the topic, and the rating of the transaction conducted by the party to the transaction associated with the topic.
14. A method comprising: selecting a document that is pertinent to a topic based on searching, using a key phrase, a plurality of documents; identifying an identifier of a party to a transaction being referenced in the document; identifying the transaction conducted by the party to the transaction based on the document, the identifier of the party to the transaction being associated with the topic; determining a rating of the transaction conducted by the party to the transaction based on the document, the determining of the rating of the transaction conducted by the party to the transaction including identifying, from a plurality of polarity words included in the document, a dominant polarity word based on a syntactic distance between the dominant polarity word and the topic in a syntactic tree, the dominant polarity word having a dominant polarity impact on the rating of the transaction conducted by the party to the transaction; and determining, using at least one computer processor, a sentiment of the document based on the transaction conducted by the party to the transaction associated with the topic, and the rating of the transaction conducted by the party to the transaction associated with the topic. 15. The method of claim 14 , wherein the method further comprises: identifying one or more documents that reference a product of a plurality of products based on detecting a topic of a set of documents wherein the topic comprises a product name; determining a user sentiment for the product based on the sentiment of the one or more documents that reference the product; and generating a product ranking that orders the plurality of products based on the user sentiment for each of the plurality of products.