2. ACT-1 Group
This employment agency is based in Torrance, California, and has more than 2,300 employees. It posted about $2.3 billion in revenue this year alone.
1. World Wide Technology Inc.
Roughly four years ago, this Missouri-based technology products and consulting service firm experienced a serious spike in demand. Revenue rose more than 40 percent to $3.2 billion in 2010. The company posted $6.4 billion in revenue in 2014.