After Tsai signed a recording deal with Universal, her debut single, "Living with the World", was released in July 1999. She then started developing her debut album, "1019", which was released in September 1999, and she received positive feedback for the album, with 400,000 copies sold in Taiwan alone. Tsai was named as the "Teenage Boy Killer" by media, and became an instant hit among teenagers in Taiwan. The lead single, "I Know You're Feeling Blue", reached number thirty on the Hit FM Top 100 Singles of the Year. In March 2000, she released her first live album, "1019 I Can Concert". Tsai achieved general recognition in Greater China after the release of her second studio album, "Don't Stop", in April 2000. The album became her best-selling album in Taiwan of her career to this date with sales of 450,000 in Taiwan alone. The title track, "Don't Stop", reached number fourteen on the Hit FM Top 100 Singles of the Year.