In July 1987, Guns N' Roses released its debut album, "Appetite for Destruction", which as of September 2008 has sold over 28 million copies worldwide, 18million of which were sold in the United States, making it the best-selling debut album of all time in the U.S. In the summer of 1988, the band achieved its only U.S. No. 1 hit with "Sweet Child o' Mine," a song spearheaded by Slash's guitar riff and solo. In November of that year, Guns N' Roses released "G N' R Lies", which sold over five million copies in the U.S. alone, despite containing only eight tracks, four of which were included on the previously released EP "Live ?!*@ Like a Suicide". As their success grew, so did interpersonal tensions within the band. In 1989, during a show as opening act for the Rolling Stones, Axl Rose threatened to leave the band if certain members of the band didn't stop "dancing with Mr. Brownstone," a reference to their song of the same name about heroin use. Slash was among those who promised to clean up. However, the following year, Steven Adler was fired from the band because of his heroin addiction; he was replaced by Matt Sorum of The Cult.