GRP cost buying refers to the process of purchasing advertising space on television or radio based on the cost per gross rating point (GRP). This method allows advertisers to reach a specific target audience by calculating the cost of reaching 1% of the total audience. GRP cost buying is a strategic approach that helps advertisers maximize their budget and effectively reach their desired audience. It takes into account factors such as the program’s popularity, time slot, and audience demographics to determine the most cost-effective way to reach a specific target market. This method is commonly used in media planning and buying to ensure that advertisers get the most value for their advertising investment.