The 10 Largest Inc. 5000 Companies
CEO: Thomas Richards
Three-Year Growth: 41.4 percent
2012 Revenue: $10.1 billion
Founded in 1984, CDW is a computer hardware retailer that also provides related IT services to the business, healthcare, education, and government industries. Founder Michael Krasny was inspired to start the business after getting a huge response to a $3 classified ad he placed in a newspaper to sell his used IBM computer. The Vernon Hills, Illinois-based company went public in June.