Serial entrepreneurs keep doing what they do for a reason. They've figured out something quitters have not: Succeeding in business is a formula. That's according to Vivek Sharma, cofounder and CEO of  Movable Ink, a New York City-based startup focused on agile email marketing that allows clients to change the content of emails once they have been delivered, based upon a recipient's context. For example, the technology can optimize an email's content or appearance based upon what device or computer a recipient is using, where he or she is located, or how a person interacts with it.

Movable Ink is the fourth startup Sharma has worked on and in the five years the company has been around it has amassed more than 100 employees as well as about 350 large clients including Macy's, Hilton, United Airlines, Home Depot and eBay. As a former student of aerospace engineering, Sharma says scaling a startup really is a physics thing that can be tied to Newton's three laws of motion. Here's how.

1. An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

Commonly referred to as "the law of inertia," it applies to startups because beginning isn't easy and takes tremendous force. And for some founders, the effort is too much and they quit. Others keep pushing in spite of the fact that no one cares about their new idea, or the fact that inertia is the normal state of things. "The ones who make it past that point and something clicks, that's the moment in startup land where we call it 'product-market fit,'" he says. "The company starts to move and suddenly it feels like you can keep closing customers because you've figured out that secret formula to make it work. And it feels amazing--by applying a little more force you start to  increase your velocity."

2. The acceleration of an object is dependent upon two variables--the net force acting upon the object and the mass of the object.

In physics the formula is Force = Mass * Acceleration. According to Sharma, in business it works like this: Force = Talent * Will * Structure. Essentially, he means your continued growth depends on three things: the talent your company possesses, your will to persevere and the right company structure built on  strong leadership and process.

3. For every action, there is an equal and opposite reaction.

Think of a rocket burning fuel and the force of that combustion shooting it into space. Lots of things happen in that scenario--a lot of movement, as well as destruction of the launch platform due to the energy involved. With a startup gaining momentum and getting noticed in an industry it means attracting other companies as partners or talented employees who want to be where the action is at. But there are negative reactions, as well. For example, competition begins to form and pricing pressure becomes a reality because other companies realize you're doing something valuable.  "You start to affect other players in your eco-system and they're either going to fight you or partner with you," he says. "So you have to think carefully about that counter-reaction that you will get as that force starts to become larger and larger."