Generally in the free market, price is determined at the point that demand and supply meet. In Korea, all terrestrial TV as well as radio advertising time has been sold through KOBACO, the public corporation of media representative since 1981. By its origin, KOBACO's ad-pricing system was neither built for the sake of networks, nor for its own. For a considerable period of time, one major factor for increasing annual ad rate was inflation rate of nation's economy. As time goes by, KOBACO has been changed. With a current effort of embracing free-market principle, KOBACO insists their pricing system reflects various factors: media characteristics, time bands, accumulated genre data, advertiser preferences, as well as supply and demand for a particular time slot. But we still doubt that KOBACO's pricing system is considerably behind to reflect a real value of ad time. Therefore our purpose of this research is to examine how well this system reflects, or related with sales-related market performance (product usage or purchasing data) in addition to the exposed audience size. ..PAT.-Unpublished Manuscript [ABSTRACT FROM AUTHOR]