Doing business around New York City is about as easy as walking up Mount Everest barefoot. It's very competitive in a region of 21 million people.

And yet, Mark Sax didn't blink when starting his own company. The recent graduate of BMG University had no personal electronic medical billing experience. In fact, he was new to the business world. But with that legendary Jersey confidence, Sax's company has nearly 20 clients in less than three years and growing faster than John Goodman's waistline.

"That's the dream -- I want to be the biggest in the world," Sax said.

ElectroBills Medical Billing Service in Lakewood, N.J. started with a unique strategy -- clinics. Why not make the first bite a whole mouthful? With general practitioners and home health care specialists, Sax convinced groups to try his fledging company. Instead of growing one by one, ElectroBills grew group by group.

"The main trigger is we jumped in on a few clinics," Sax said. "We work with all the doctors in the clinics."

Sax had an ace up his sleeve -- his wife Dina worked for a Cleveland medical firm for eight years as a biller so she knew the basics of the business. It also helped grab a client from Ohio despite being several states away. Now ElectroBills has six employees.

Sax learned growth is a mixed blessing, though. You better be in front of it or clients will be unhappy and business will suffer. It takes two things for a medical billing company to succeed -- great software and standout customer service.

Fortunately, Sax chose ClaimTek Systems for its MedOffice software. The system is the leader in practice management through its ease of use and interactiveness with client offices.

"It's a very good software," Sax said. "They do nice work and updates on it. I've seen what's out there. There's a lot of competition with these software."

Just like Sax needs to provide standout support for clients, he requires the same from his software company. That's where ClaimTek owner Kyle Farhat and his staff stand out.

"Kyle's very supportive. He's helped us with different ideas," Sax said. "He's been there for us. He knows the software backwards and forwards."

Sax knows good customer relations given it's critical to his own success. The key to making his clients happy -- work hard for them.

"You have to always make sure the clients are happy," Sax said. "It's all about charming these people. We take it day by day, client by client. We don't go out there to get another client. We make sure we can handle everything we have. I can't jeopardize a client to get another client. We make sure everything under control, everything's working. Then I'll try to get somebody else [as a client]."

That customer service even extends to dealing with insurance companies on the doctor's behalf.

"One customer told me 'You don't know what kind of impression you made now that Medicare realizes how nice we are,' " Sax said. "It made them look good in [Medicare's] eyes."

One way to please clients is handling overdue accounts receivables. Cleaning up the past mess isn't easy without software like MedOffice to organize it.

"A lot of [accounts] were messed up. We had to go back and fix all their problems," Sax said. "It was brutal, but your job is to get it done. That's your job."

And it's not a bad job given the economic recession. Sax recommended electronic medical billing to those wanting to start their own business for its unlimited growth potential. Not many other industries can truthfully make that claim nowadays.

"It's tough to make a living nowadays," Sax said. "If anybody's going to get into business now, the business to get into is health care. People are always getting sick."

But not sick of successful companies like ElectroBills.