1. A method for use in personalizing advertising for a user, the method comprising: accessing information indicating which documents in a set of documents were selected by a user for viewing and which documents in the set of documents were not selected by the user for viewing; generating at least one positive word vector using words contained in at least a segment of at least one of the documents that was selected by the user for viewing; generating at least one negative word vector using words contained in at least a segment of at least one the documents that was not selected by the user for viewing; generating document word vectors for at least some of the documents that were selected by the user for viewing; performing, using at least one processor, a vector space relationship analysis of the positive word vector, the negative word vector, and the document word vectors; establishing, using at least one processor, a document rank order of the documents selected by the user for viewing based on the performed vector space relationship analysis; classifying the documents selected by the user for viewing in predetermined categories; ranking the predetermined categories based on the document rank order; sending the ranked categories to an ad server; and receiving advertisements associated with the ranked categories from the ad server in a selected context.