When Ray Kroc was a milkshake-machine salesman, he noticed that one restaurant, in California, was buying more machines than anyone else, so he went to visit his best customer — McDonald’s. The rest is entrepreneurship history.

When Howard Schultz was an espresso-machine salesman, he noticed that a company in Seattle was buying more machines than anyone else, so he went to visit his best customer — Starbucks. What followed there is also entrepreneurship history.

They could have simply built the customer relationships, returned to their jobs, and enjoyed their growing commissions. Who knows? They might have reached $100,000 or more in annual commissions and lived comfortably ever after. Instead, their intellectual curiosity, their willingness to think outside the box, and their passionate belief that their vision was the right vision enabled them to forsake the comfort and security of their jobs and earn wealth beyond any imagination — except for entrepreneurial imagination.

Lloyd E. Shefsky Founder and Co-Director Center for Family Enterprises Northwestern University Evanston, Ill.

Before it's here, it's on the Bloomberg Terminal. LEARN MORE