1. A system to recommend a keyword, the system comprising: a verifying unit to determine whether a keyword is a direct click keyword by referring to a click log and to determine whether the keyword is an indirect click keyword by referring to a third universal resource locator (URL) selected in response to using the direct click keyword, wherein the direct click keyword is a keyword used to select a first URL on a computing device and the indirect click keyword is a keyword used to select a second URL on the computing device; and a keyword recommending unit to recommend the determined indirect click keyword.