Olympic Boulevard has blocks dominated by Korean-language signs and new blue-tile-roofed shopping centers. This initial Korean business area has spread to an area bounded by Olympic Boulevard, Vermont Avenue, 8th Street and Western Avenue. The Korean business area also sprawls to the north and south along Western and Vermont for three miles, and to the east and west along Olympic for two miles. South Korean investment has been a large contributor to the neighborhood economy since the 1960s. Since the early 2000s, that investment has increased greatly, ballooning to an estimated $1 billion in new construction investment. Jamison Services, Inc is Koreatown's biggest landlord and most prolific residential builder. The area also has a vibrant nightlife with many lively restaurants and clubs, especially Korean barbeque restaurants and karaoke bars.