Staffmark Group | 12,528 followers on LinkedIn. Staffmark Group is one of the largest staffing companies in the United States and is a portfolio company of RGF Staffing and Recruit Group, an $23.62 billion global HR services provider. For more than 55 years, Staffmark Group has delivered the industry’s widest range of comprehensive workforce solutions through its family of specialty brands, including Advantage Technical, Hunter Hamilton, Digital People, Advantage xPO, Employee Management Services and Staffmark. Operating across a network of over 400 branches and 250 onsite locations, Staffmark Group places over 175,000 talented individuals annually.