 "Day by Day" became one of the most successful singles of all-time in South Korea, selling over 5.4 million digital downloads in the country alone.Teasers for the album was released on August 1, including the announcement that Japanese DJ Daishi Dance had collaborated with the group on a song.Released on August 8, 2008, the EP debuted at the number two position, selling more than 30,000 copies in two days, and selling 100,000 units in two weeks.