1. A computer implemented search result providing system, comprising: a non-transitory storage device having one or more units, executable by a processor, the one or more units including: a registration keyword determining unit configured to determine a registration keyword based on a correlation between at least one word of an input keyword received from an advertiser and at least one information of advertising contents of the input keyword, the at least one information of advertising contents including title and description (T&D) information and website information corresponding to a universal resource locator (URL) of the T&D information that are associated with a registration of the keyword; a registration keyword registration unit configured to register the registration keyword targeted to a search result associated with the input keyword based on the determination; and a search result exposing unit configured to provide search results based on one of the input keyword, additionally registered registration keyword, or both the input keyword and the additionally registered registration keyword corresponding to an input query; a registration keyword updating unit configured to update the registration keyword according to at least one change of the at least one information during a threshold period of time; a keyword set generator configured to perform a clustering with respect to a plurality of keywords to generate and maintain at least one keyword set based on whether a keyword is purchased or an advertisement performance according to an input keyword or a registration keyword, wherein the registration keyword determining unit is configured to determine the registration keyword based on at least one keyword among keywords in the keyword set; a determining function provider configured to determine to expose advertisement selectively using the input keyword or additionally registered keyword causing by determining function being selected; and a search result exposing unit configured to expose a search result in response to receipt of a search keyword transmitted from a user terminal corresponding to at least one of the input keyword, additionally registered keyword or the both of the input keyword and the additionally registered keyword.