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. With its acquisition of Nashville, Tennessee-based brokerage Benchmark Realty in 2020, the United brand now has over 12,000 agents in 24 states who do over $15 billion in annual sales.