Kookmin Card (KB Card hereafter) is the first credit card in Korea. KB Card has reached 1 billion won of usage domestically in 1996. By stabilizing the computerized system and process and investing enthusiastically on adopting the new technology and system, KB Card introduced the first deferred pay traffic card in the world, won a place in the Guinness Book of Records, and realized a ‘Welfare Boucher card’ utilizing the IC chip in the public welfare section. Separated from the Kookmin Bank in 2011, KB Card became a leader in the industry. The KB ‘Hae-dam’ card led the new market of one-card, and changed the paradigm of credit card industry. KB Card is now trying to bolster its marketing with the use of big data. After endless discussions, KB Card has set up a system to execute real-time marketing that utilizes big data. The system is based on actual life-cycles of the customers, accounting up to 280 kinds of possible scenarios to meet the real-time demand of diverse customer segments. For example, KB Card is accumulating inside and outside information of local business districts in order to provide a more accurate and effective restaurant ranking. Also, to target the ‘moms’ segment centered around childbirth and child-rearing, KB Card is utilizing accumulated data on the main consumers to provide discounts and offers customized to the child’s age. Lastly, by analyzing the lifecycle of the customers, KB Card is preparing diverse campaigns that can respond to the similar patterns in consumer lifecycle. The project is planned to be executed in full scale soon. Although real-time messages are partly utilized in other firms, an exclusive system will be helpful for KB Card to implement its real-time marketing plans. This case examines various marketing activities and big data strategies of KB Card.