Bill Duncan completed the Advanced Management Programme through Macquarie University's Graduate School of Management, is qualified in Association Management through Monash University's Mt. Eliza Graduate School, and is a certified mediator in dispute resolution. Having been involved in direct selling and network marketing for more than a quarter century, his past experience involves working as an economics teacher, educational publisher, army officer, corporate lawyer, community leader, general manager, and board director/chairman of various government and industry organizations.

Bill learned his business disciplines while working for IBM, after which he mentored field leaders in multi-level marketing with Amway where he progressed through a succession of senior executive and management roles.

Bill became managing director of USANA Australia in December 2000 following his management of projects for the Paralympic Committee for the Sydney Olympic Games and is chairman of the Direct Selling Association of Australia and GROW Sydney—the Australian government's largest area consultative committee. In 2006, Bill was named USANA’s vice president of Australasia, and in 2008, he was promoted to executive vice president of Australasia, which is comprised of the Singapore, Malaysia, New Zealand, and Australian markets.