Cyrus Massoumi

The pitch is simple: Rather than try to book an appointment with your busy doctor by phone, do it online at ZocDoc. Patients seem to dig it; the site has more than 1 million users and $95 million in funding, and won't even be nationwide until 2013. (It's in 16 cities now.) But the sell to docs and investors wasn't easy.

5 steps to: Winning over doctors

Step 1: Start with dentists

Patients visit them frequently and schedule visits long in advance. That makes dentists a natural entry point, Cyrus Massoumi believed.

Step 2: Get kicked out, come back

Most dentists didn't see a need for ZocDoc; Massoumi was kicked out of multiple offices. But he kept calling. "Now they're all our clients," he says.

Step 3: Sign up 10 doctors

Ten is a magic number, Massoumi says: At that point, he could tell other dentists that their peers were signing on, and selling became much easier.

Step 4: Follow the geography

ZocDoc's first market was New York, where one in six primary-care doctors are trained. Local docs told out-of-town friends, and Massoumi followed.

Step 5: Arm with early data

As the system went live, ZocDoc found that 80% of first-time users stuck with it. ZocDoc used that selling point to impress and sign up specialty doctors.

3 steps to: Winning over VCs

Step 1: Identify the culture clash

Because Massoumi and his partners were previously McKinsey & Co. consultants, he says, "the startup community really questioned us."

Step 2: Buy jeans

"I literally went to the Gap, bought jeans, and untucked my shirt. I was suddenly rebranded. And there was our cred."

Step 3: Meet and greet

In meetings with VCs, he was less formal and more direct. Now, finally, he was speaking like the startup guy he'd become.