Legend accounted for 87.5 percent of Shanda Interactive's revenue in the first quarter of 2004. To reduce dependence on those two games, Shanda released the self-developed game The Sign in February 2004, and by April was also working on the in-house titles Age and Magical Land. Shanda Interactive listed on the NASDAQ in May 2004, raising $152 million with the initial public offering (IPO) under the ticker SNDA and becoming the first Chinese online games company listed in the United States. At the time it was the largest IPO of a Chinese internet company in the United States, and shortly afterwards Shanda became the largest internet company by market capitalization in China. In October 2004 Shanda issued US$275 million convertible notes to be redeemable in October 2007. That month Shanda was operating eight games and hosting 1.2 million simultaneous players. As of May 2005, 300,000 locations, among them 130,000 internet cafes, sold prepaid cards for Shanda's games and game usage was "up 70% from a year earlier." Shanda purchased about 20% of Sina.com for $230 million in 2005, becoming Sina's largest shareholder. Operating as an online advertising firm, Sina.com was the most popular internet portal in China at the time. Also that year Shanda purchased the mobile game provider Digital-Red and the literature website Qidian. In 2005, Shanda also began working with search engine Baidu and partnered with Universal Music Group to support music streaming on PCs in China. Shanda revealed two hardware products in October 2005. The EZ mini was a handheld wireless gaming device, while the EZ Center/EZ Pod software for was remote PC control. Shanda employed 2,000 game developers at its headquarters at the end of 2005, and had recently purchased motion-capture equipment to speed the animation process. With six game titles at the time, four of those had been developed in-house. On average, Shanda's revenues doubled each year between 2001 and 2005, and at the end of 2005 it had a market capitalization of $1.8 billion and was China's biggest gaming company. Founder Chen Tianqiao was estimated to have a net worth of $1.45 billion, with the press dubbing him the "Chinese Bill Gates." 2005-2007: Free-to-play model In the summer of 2005, Shanda Interactive's revenue dropped significantly as its old hit Legend of Mir II began to lose subscribers. With the intent of extending the life of its older MMORPGs, in December 2005, Shanda announced that