Pierce was born in Minnesota, and appeared in commercials as a toddler. His first major role was playing a young Gordon Bombay in The Mighty Ducks (1992). Pierce reprised the role in D2: The Mighty Ducks. He starred as Luke Davenport in First Kid (1996). Pierce had small roles in Little Big League (1994), Ripper Man (1995), Problem Child 3 (1995), Three Wishes (1995), and Earth Minus Zero (1996).

In 2001, Pierce founded Internet Gaming Entertainment (IGE), a company which pioneered the MMORPG currency-selling services industry. Between 2004 and 2005, IGE spent more than $25 million buying out seven smaller competitors, including four auction platforms and a number of fan and content sites. In 2005, Pierce estimated that IGE accounted for about 50% of this online market in the U.S., which has about $500 million in annual volume.

Pierce founded ZAM, a network of websites oriented around massively multi-player online role-playing games (MMORPG), such as World of Warcraft, Star Wars: The Old Republic, Rift, EverQuest, etc., in 2003. The ZAM.com network included Gaming websites such as ZAM.com, Wowhead, Thottbot, Torhead, and D3DB.

Pierce brought in Steve Bannon, the then former Goldman Sachs banker, to seek venture capital and a deal was made in February 2006 yielding $60 million of which Pierce took away $20 million for a minority stake. The next year, facing a class-action lawsuit, the company failed, had no assets and Pierce was forced out.

In 2010, Titan Gaming recruited Pierce to sit on its board along with EA Executive Keith McCurdy. Pierce joined other Southern California angel Investors, including MP3.com's Michael Robertson, SOA Software's Eric Pulier and william Quigley and Jim Armstrong of Clearstone Ventures. Also that year, Titan Gaming purchased the rising online Gaming network Xfire from Viacom. In October 2011, after Xfire received over $4 million in fresh funding from Intel Capital, Titan Gaming and Xfire cut ties and went their own ways. Titan Gaming and Xfire now operate independently. In late April 2012, Titan Gaming announced that it would be rebranded as Playsino to embark in a complete makeover, with Pierce as the new CEO and $1.5 million of new funding.

As of 2013, Pierce was managing Director of the Clearstone Global Gaming Fund a board member of IMI Exchange (a remnant of the IGE restructuring), Xfire, Playsino (having been replaced as CEO in 2013), GoCoin, FGL, Spicy Horse Games, KnCMiner.cn and the Mastercoin Foundation. He was also a member investor of Bit Angels and an investor in BTC China.

Pierce was elected Director of the Bitcoin Foundation in May 2014. Several members of the Bitcoin Foundation resigned after his election due to the previous allegations of sex abuse against Pierce. The organisation announced its insolvency in July 2015.

In a February 2018 issue of Forbes magazine Pierce was named in the top 20 wealthiest people in Crypto with an estimated net worth between 700 million and 1.1 Billion.