According to the Wall Street Journal, there are 2.7 million people in the United States with a net worth of $1 million or more, part of a 8.7 million worldwide population of millionaires. Americans with investment assets of more than $30 million top 30,000. And according to Forbes magazine, there are now more than 374 billionaires in America. The average millionaire is 57, and the average billionaire is only 59.

Contrary to older ideas, only about 20 percent are born into money. Most millionaires come from seemingly humble beginnings, and a few make it big by developing a revolutionary product or a breakthrough technique. But more are simply workaholics who start by owning a small business.

If you have prospected for millionaires in the past, you probably searched for social class and the trappings of wealth. Yet only half of these families own and occupy homes of $600,000 or more. Many people are more interested in appearing to be wealthy than developing the discipline necessary to achieve millionaire status. In fact, many salespeople are trained to hunt big game among those working in medical facilities. But often the lifestyles of physicians are defined by the expectations of society. Since they are in a prestige working position, they find themselves better credit customers than candidates for expensive real estate. They frequently live beyond their means.

Recently a business broker friend mentioned that among the medical practices she handled, few physicians made more than $200,000. In fact, in the 1990s, insurance companies started squeezing physician claims to such an extent that only the most business savvy were able to make more than $250,000 per year. Still, the highest paid specialists are ophthalmologists who charge $5,000 for a 15 minute LASIK procedure. And often make more than $1 million a year for their efforts.

If not doctors, then where does one snare the real goliaths of the well-heeled? Discovering where they work and live may surprise you. Ten of the most affluent are: commercial printing, dry cleaning, jewelry retailing, legal services, specialty tool manufacturing, real estate development, refuse services, real estate brokerage and property management, industrial plastics manufacturing and commercial machines and equipment wholesaling. These don’t seem to be glamorous, high-affluence categories, yet they may be your best bet for trapping prospects who won’t say they can’t afford it.

Next month: Now that you know who they are, and where they live, how do you go after their business?