The second single, "Girls' Generation", written and produced by Lee Seung-Chul and Song Jae Jun, was released on November 1, 2007. The song was originally sung by Lee Seung-Chul in the 1980s. The original singer later appeared on KM's M!Countdown with the group to perform the song together.
In early 2008, Girls' Generation began promoting their third single, "Kissing You". The song won the group their first K-chart win, after achieving the number one position on the KBS's Music Bank February chart. It also achieved the number one spot on three major TV music rankings: SBS's Inkigayo, Mnet's M.Countdown! and KBS's Music Bank. The music video for the song contained scenes of the Making of video of the Girls' Generation MV, and footage of the girls working on their first album.
The fourth single, "Baby Baby" was released on March 17, 2008. It was the lead single of the repackaged album of the same name.
Within its first month of release, the album sold 49,438 copies and was the 2nd best-selling album of November 2007 in South Korea, only behind Super Junior's Don't Don. The album sold a total of 56,804 copies in 2007, becoming the 12th best-selling album of the year in the country. The album surpassed 100,000 sales mark in March 2008; in doing so, Girls' Generation became the first girl group to achieve such a feat after S.E.S. for six years.
As of September 2008, the album's total sales figures combined with those of the reissue Baby Baby have exceeded 126,269 units.