Patent ID: 7673253

Claim:
A method, performed by one or more server devices, comprising: retrieving, by a processor of the one or more server devices, a document; indirectly inferring, by a processor of the one or more server devices, concepts associated with the document, where the concepts are not directly inferred from characteristics of the document and where indirectly inferring concepts associated with the document comprises: identifying, by a processor of the one or more server devices, a plurality of second documents that each include a link pointing to the document, determining, by a processor of the one or more server devices, which second document of the plurality of the second documents has been frequently used to access the document, extracting, by a processor of the one or more server devices, concepts associated with the second document that has been frequently used to access the document, determining, by a processor of the one or more devices, which advertisements contained in the document have been accessed from the document more than a threshold number of times, extracting, by a processor of the one or more devices, a uniform resource locator (URL) associated with each of the advertisements that have been accessed from the document more than the threshold number of times, retrieving, by a processor of the one or more devices, third documents corresponding to each of the URLs, and extracting, by a processor of the one or more devices, concepts from each of the third documents; and associating, by a processor of the one or more server devices, the inferred concepts with the document.