16. A computer-implemented method for building a user profile for a user, the method comprising: labeling and storing, with a computing device, user registration information in a database as a set of demographic nouns; determining, with a computing device, a composite set of taxonomic nouns, the composite set of taxonomic nouns representing the user profile based upon taxonomic nouns, the taxonomic nouns being prepared by one or more of the following steps: analyzing, with a computing device, author-generated classification information regarding at least one document of a set of documents and assigning a set of first taxonomic nouns to characterize the user based upon the author-generated classification information; examining, with a computing device, a user-generated tag from a client computer and characterizing the user of at least one document of the set of documents and assigning a set of second taxonomic nouns to characterize the user based upon the user-generated tag characterization; identifying, with a computing device, a method by which the user accessed at least one document of the set of documents from a content provider and assigning a set of third taxonomic nouns to characterize the user based upon the search term; evaluating, with a computing device, attributes that are related to the method of access and assigning a set of fourth taxonomic nouns to characterize the user based upon the attributes related to the method of access; and processing, with a computing device, at least one document of the set of documents to extract a set of fifth taxonomic nouns to characterize the user; building, with a computing device, the user profile, the user profile based upon the composite set of taxonomic nouns, the author-generated classification information, and at least one of the demographic nouns; comparing, with a computing device, the composite set of taxonomic nouns with taxonomic nouns associated with a plurality of other user profiles corresponding to a plurality of other users; and modifying, with a computing device, the user profile based on the comparison.
16. A computer-implemented method for building a user profile for a user, the method comprising: labeling and storing, with a computing device, user registration information in a database as a set of demographic nouns; determining, with a computing device, a composite set of taxonomic nouns, the composite set of taxonomic nouns representing the user profile based upon taxonomic nouns, the taxonomic nouns being prepared by one or more of the following steps: analyzing, with a computing device, author-generated classification information regarding at least one document of a set of documents and assigning a set of first taxonomic nouns to characterize the user based upon the author-generated classification information; examining, with a computing device, a user-generated tag from a client computer and characterizing the user of at least one document of the set of documents and assigning a set of second taxonomic nouns to characterize the user based upon the user-generated tag characterization; identifying, with a computing device, a method by which the user accessed at least one document of the set of documents from a content provider and assigning a set of third taxonomic nouns to characterize the user based upon the search term; evaluating, with a computing device, attributes that are related to the method of access and assigning a set of fourth taxonomic nouns to characterize the user based upon the attributes related to the method of access; and processing, with a computing device, at least one document of the set of documents to extract a set of fifth taxonomic nouns to characterize the user; building, with a computing device, the user profile, the user profile based upon the composite set of taxonomic nouns, the author-generated classification information, and at least one of the demographic nouns; comparing, with a computing device, the composite set of taxonomic nouns with taxonomic nouns associated with a plurality of other user profiles corresponding to a plurality of other users; and modifying, with a computing device, the user profile based on the comparison. 24. The computer-implemented method for building a user profile of claim 16 , wherein the attributes related to the method of access include at least one of sharing the user's interests, clicking on a newsletter, participating in a discussion, reading or writing a blog, downloading a white paper, purchasing a product or a service, reviewing a product or service, sharing a document, posting to a social network, sending an email, and disclosing information about the user.