Well, based on 2004 data about one-thirtieth of one percent of Americans are doctors. In contrast, more than one percent of Americans are in jail. So....thirty times more people in America are in jail than are doctors. Doctors are certainly more succesful than those in jail, although a far smaller portion of the population.
I'll bet most of the American public would agree that, as a rule, doctors are more succesful than the average college grad. Only 28% of Americans have at least a Bachelor's degree, and I'd say they are more succesful than most high school grads. Let's face it-- money is one good way to gauge "sucess" and college grads average $51,206/year, while those with just a high school diploma get $27,915. Of course the hs diploma guys are more successful than the non-diploma guys who average $18,734.
Of course, there are some cultures who value machismo more than money and the migrant worker with 72 kids would be more "succesful" than the childless software engineer worth a billion dollars. And how about the geeky 24 year old who lives with his mom, bags groceries to pay for a lifetime supply of Proactive and has never been on a date. Yet, he advanced 60 levels in three hours in the latest online video game craze. Hmmmmm...a certain segment of the population would call him "succesful" too. The "succesful" women from my home town were able to find a man who could keep a job for more than a year, afford a doublewide trailer to live in and not cheat on them too much in public.
When you consider things, I believe just graduation from a DO or MD school is a pretty darned nice accomplishment.