Milwaukee-based ManpowerGroup is the largest specialized firm in the fragmented global staffing industry. It serves each main staffing category--temporary, permanent, and project-based--and also offers a suite of HR outsourcing and outplacement services. Manpower generates annual revenue and operating income of more than $20 billion and roughly $800 million, respectively. A vast majority of sales are generated outside the U.S. from operations in 80 countries. Its 30,000 employees serve an estimated 600,000 clients and place millions of job candidates.