Fils-Aimé has served as the Head of Marketing for Guinness in the United States and was responsible for all brands. He also worked as Chief Marketing Officer at Derby Cycle Corporation, directing sales and marketing efforts for eight brands. Fils-Aimé served as Managing Director and oversaw Derby's British operations.
He then joined the world's Chinese food service leader, Panda Management Co., acting as Senior Vice President. Later, he came on board to VH1 as Senior Vice President. He was responsible for a 30% increase in ratings by refocusing the channel's content to appeal to younger viewers.
On May 25, 2006 Fils-Aimé became the President and Chief Operating Officer of Nintendo of America after former president, Tatsumi Kimishima, was moved to his new role as Chairman of the Board and Chief Executive Officer. Fils-Aime is the first American to hold this position.
Fils-Aimé shot to fame in May 2004 with the opening line of Nintendo's E3 press conference: "My name is Reggie. I'm about kickin' ass, I'm about takin' names, and we're about makin' games." His theatrical antics gained a cult following soon after, with many gamers calling him the "Regginator" and video games podcast Angry Gamer turning him into a recurring character on their show. Following the conference, many images of him spread across the Web. Reggie is considered by some to be responsible for revamping Nintendo's public relations in North America, leading many fans and members of the press to dub his arrival the "Reggielution" (after "Revolution", the code name for the Wii).
He has attributed the success of the Wii to a marketing strategy laid out by Clayton Christensen:
On November 5, 2007, at the encouragement of a professor in the department of Applied Economics and Management at Cornell University, Fils-Aimé gave a guest lecture on Nintendo's marketing strategy targeted at gamers across a spectrum of demographics.