6. A computer-implemented method comprising: receiving, by a computing system, a source web page document; identifying, by the computing system based on formatting information of the source web page document, a plurality of regions contained within the source webpage document, that would be displayed to a user visiting said source web page document, wherein the regions contained within the source webpage document contain content between opening and closing HTML or XML tags; determining, by the computing system, at least one local concept expressed within each previously identified region, wherein determining the at least one local concept comprises identifying words in the document and aligning the words with concepts, wherein said at least one local concept expressed within said each previously identified region is a concept expressed by two or more words contained within the region; determining a score for a local concept expressed in each previously-identified region, wherein the score is based on an importance associated with the previously-identified region; analyzing, by the computing system, the previously determined at least one local concept of each region to identify and eliminate from consideration one or more local concepts that are unrelated to local concepts of other of said previously identified regions by creating a ranked global list of all of said local concepts; analyzing, by the computing system, the previously identified regions to identify and eliminate from consideration one or more regions that are unrelated to other previously identified regions by comparing a ranked list of local concepts for each of said previously identified regions to said global list; determining, by the computing system, a source meaning for the source web page document, wherein the source meaning for the source web page document is a weighted vector of said previously determined local concepts expressed in the source web page document that remain after the eliminations; and matching, by the computing system, the source web page document with an item selected from a set of items by comparing the previously determined source meaning and a meaning of the item.
6. A computer-implemented method comprising: receiving, by a computing system, a source web page document; identifying, by the computing system based on formatting information of the source web page document, a plurality of regions contained within the source webpage document, that would be displayed to a user visiting said source web page document, wherein the regions contained within the source webpage document contain content between opening and closing HTML or XML tags; determining, by the computing system, at least one local concept expressed within each previously identified region, wherein determining the at least one local concept comprises identifying words in the document and aligning the words with concepts, wherein said at least one local concept expressed within said each previously identified region is a concept expressed by two or more words contained within the region; determining a score for a local concept expressed in each previously-identified region, wherein the score is based on an importance associated with the previously-identified region; analyzing, by the computing system, the previously determined at least one local concept of each region to identify and eliminate from consideration one or more local concepts that are unrelated to local concepts of other of said previously identified regions by creating a ranked global list of all of said local concepts; analyzing, by the computing system, the previously identified regions to identify and eliminate from consideration one or more regions that are unrelated to other previously identified regions by comparing a ranked list of local concepts for each of said previously identified regions to said global list; determining, by the computing system, a source meaning for the source web page document, wherein the source meaning for the source web page document is a weighted vector of said previously determined local concepts expressed in the source web page document that remain after the eliminations; and matching, by the computing system, the source web page document with an item selected from a set of items by comparing the previously determined source meaning and a meaning of the item. 10. The computer-implemented method of claim 6 , further comprising displaying content associated with the matched item on the source web page document.