1. A system comprising: a receiver to receive a search query; a first associator to associate a first numerical value with a first keyword that is a part of the search query, the first numerical value being based on usage of the first keyword in a plurality search queries; a tracker to track user activity associated with the first keyword; a second associator to associate a second numerical value with the first keyword based upon the user activity, the second numerical value being based on determinable user activity associated with the first keyword; a calculator to determine a difference value between the first and second numerical values, and to associate the difference value with the first keyword; a sorter to sort a plurality of keywords based upon respective difference values associated with each keyword of the plurality of keywords; and an outputer to output a result of the sort.