1. A computer-implemented method of extracting search terms from a log, comprising: accessing, using one or more data processors, a log containing a plurality of search strings compiled from previously executed searches submitted to a plurality of different known and new search engines; parsing, using the one or more data processors, a search string from the log containing the plurality of search strings from previously executed searches to identify one or more name-value pairs within the search string, wherein a name-value pair is associated with a variable name and a variable value; searching, using the one or more data processors, a non-search term table to identify the variable name or the variable value associated with each name-value pair, wherein the non-search term table includes variable names or variable values known as non-search terms for known search engines; determining, using the one or more data processors, that a variable value associated with a name-value pair is not a search term when the associated variable name or the variable value is located in the non-search term table, wherein name-value pairs having associated variable names and variable values that are not located in the non-search term table are remaining name-value pairs; searching, using the one or more data processors, a search term table to identify the variable name or the variable value associated with each remaining name-value pair, wherein the search term table includes variable names or variable values known as search terms for known search engines; determining, using the one or more data processors, that a variable value associated with a remaining name-value pair is a search term when the associated variable name or the variable value is located in the search term table, wherein remaining name-value pairs having associated variable names and variable values that are not located in the search term table are unknown name-value pairs; and applying, using the one or more data processors, a name-value pair test to determine whether the variable values associated with each unknown name-value pair are search terms, wherein the name-value pair test identifies search terms associated with new search engines.