17. A computer readable medium having computer code thereon, the medium comprising: instructions for receiving a collection of text-based terms associated with a document; instructions for performing a statistical analysis on the text-based terms to identify a distribution and relative frequency of the text-based terms in the document; instructions for receiving a listing of multiple themes associated with the document, the listing of multiple themes being derived as a result of performing a semantic analysis of the document; and instructions for utilizing the distribution and relative frequency information derived from the statistical analysis to rank the multiple themes.
17. A computer readable medium having computer code thereon, the medium comprising: instructions for receiving a collection of text-based terms associated with a document; instructions for performing a statistical analysis on the text-based terms to identify a distribution and relative frequency of the text-based terms in the document; instructions for receiving a listing of multiple themes associated with the document, the listing of multiple themes being derived as a result of performing a semantic analysis of the document; and instructions for utilizing the distribution and relative frequency information derived from the statistical analysis to rank the multiple themes. 21. The computer readable medium as in claim 17 further comprising: instructions for generating document metadata including the ranked themes; instructions for associating the document metadata to the document; and instructions for distributing the document metadata to at least one remote process that utilizes the ranked themes to identify relevant advertisements for displaying to a user upon retrieval of the document by the user.