Duffy leads the large real estate network United Real Estate Group, which operates residential, country and auctioneering divisions. Its residential division operates with an agent flat-fee business model with both company-owned and franchised offices. In 2020, it acquired Nashville, Tennessee-based brokerage Benchmark Realty. The group now has an estimated over 10,000 agents in 24 states who do over $13 billion in annual sales.