July 3, 2007 — -- If it's got Oprah's name on it, it's got to be good.
At least that's the consensus of most Americans, who tune into her hit talk show, snatch up her magazine and click more than 68 million page views a month on her Web site. And she's charitable too: The Oprah Winfrey Leadership Academy for Girls in South Africa opened its doors in December.
It seems like everything Winfrey touches turns to gold.
And it looks like she's about to rack up quite a few more doubloons.
The newest addition to the Winfrey empire, a store in downtown Chicago located just across the street from her show's studio, is currently in the planning stages. The retail space will sell items similar to those available in her Web site boutique and will presumably add to the celebrity's popularity -- not to mention her net worth.
Similarly, Donald Trump's business acumen has landed him everything from his own reality show to lines of eponymously titled vodka, bottled water, steaks and even Trump University, a school that teaches -- you guessed it -- business management.
Celebrity entrepreneurs like Martha Stewart and Steve Jobs work just as hard to carve their niche in the marketplace.
Will these mega-ambitious moguls -- already richer than the average person could ever imagine -- ever stop expanding on their self-made brands?
According to one expert, many successful business people may have a genetically based temperament that is actually considered manic.
John Gartner, the author of "The Hypomanic Edge" and an assistant professor of medical psychology at Johns Hopkins Medical School, told ABC News that the ambitious nature of people like Winfrey and Trump could be attributed to hypomania, a condition that elevates a person's energy, creativeness and willingness to take risks.
"It's a temperament that is similar to mania but is milder, and so more functional," said Gartner. "The energy, the confidence, the risk-taking and not needing much sleep are physiological traits that people are born with, and you do see them in people like Oprah Winfrey and Donald Trump and Steve Jobs."
"A little bit of mania seems to be correlated with success and ambition," said Gartner. "These are people who are very highly motivated biologically -- their motivational sensors are firing at a very high rate."
Their bank accounts are similarly over the top.Winfrey is consistently pegged as one of the most influential people in the world by Time magazine, and is currently ranked No. 1 on Celebrity 100, Forbes' list of the world's most powerful and best-paid celebrities. According to Forbes.com, Winfrey rakes in a whopping $250 million a year.
Trailing Winfrey, Trump is ranked No. 19 on the Celebrity 100, earning $32 million a year.
"Their motors are always revving and it's painful not to work and not to be pursuing some big ambition," said Gartner.
Whether you're predisposed or not, ambition and success require a unique combination of a few specific characteristics.
Dr. Carol Dweck, a professor of psychology at Stanford and the author of "Mindset: The New Psychology of Success," told ABC News that there are three basic factors that motivate ambition.
Individuals must have a desire to make a contribution or fight for a cause, or a passion in a certain area or a longing for fame and fortune -- often times in an effort to prove their worth, according to Dweck.
"Many people have a combination," said Dweck. "Oprah may not be in it for the fame and power and she may be in it for helping people and growing her own personal qualities. But the fame and power gives her the leverage to fulfill her mission."
And while it may seem like Winfrey has the magic touch, the secret behind her ambition and success isn't actually all that secret.
Dweck says that the amount of hard work a person dedicates to their cause determines how successful they become. Just being Oprah isn't enough, she said.
While many experts attribute ambition to genetics, the history of ambition is more complex.
The late behavioral psychologist Dr. David McClelland, long affiliated with Harvard University, explained ambition and success by analyzing early childhood experiences.
According to Angela Duckworth, an assistant professor at the Department of Psychology at the University of Pennsylvania familiar with his work, McClelland believed that ambition stemmed from a deep unconscious drive. Kids who were more independent and whose parents demanded a lot from them tended to be more ambitious in the long run.
"Someone like Oprah with her success could have given up a long time ago and lived the good life," said Dr. Joseph Renzulli, the director of the National Research Center on the Gifted and Talented. "But I think that she has this mission that is trying to make the world a better place.
It's this mission that makes ambitious people almost incapable of being satisfied.
"As soon as they accomplish something they want to accomplish the next best thing," said Gartner. "There is a tendency to move the goal posts and to expand the sphere of their ambition to a point where it's overly grandiose."
"There is no stopping point," Dweck agreed. "You can always help more people and if you have a passion for what you do that feeds on itself. And if you want fame and fortune to prove yourself that doesn't end either."