Ryan Serhant's first day in sales began on Monday, September 15, 2008. He remembers it because it's the day Lehman Brothers filed for bankruptcy, marking the beginning of the subprime mortgage crash and the great recession. Serhant made $9,000 in his first year. Nine years later, he closed 472 real estate deals totaling $1 billion in sales. 

In his new book, Sell It Like Serhant, the star of Bravo's Million Dollar Listing New York reveals specific formulas anyone in any business can use to sell a product, service, or themselves.

Don't sell products--make friends first.

My big takeaway from the book is that everyone you meet is a potential client. Serhant sold apartments to people he met at the gym, in line at Starbucks, and seated next to him at restaurants. "Everyone you encounter throughout your day represents a potential sale," he writes.

Here's the key. According to Serhant, everyone you meet is a potential sale if you connect with them first. People don't like to be sold. Never start a conversation or a relationship by talking about the product. "Start with a simple connection and let it slowly develop into something bigger," says Serhant.

Serhant's advice resonates with me because I read his book on a flight home from Orlando, where I had given a speech to leaders in the aviation industry. I owed the gig to a short conversation--at Starbucks, where a man introduced himself to me.

He was a former CEO who had recommended one of my books to his entrepreneurship class. I suggested that I drop in and take questions from the class. He took me up on it. The relationship began with no expectation of a "sale." Two weeks after I met the students, I receive a call out of the blue from a conference organizer who invited me to give the keynote speech at their November conference. The CEO had recommended me.

When I called the CEO to thank him, he said, "I always take care of my friends."

Serhant is right. What starts as a simple connection at Starbucks can grow into something bigger. Nobody wants to be sold, but they want to help their friends.

Serhant has a three-step formula to be build stronger client relationships: follow-up, follow-through, and follow-back.

1. The Follow-Up

You might be ready to make a sale, but your client might not be ready to buy. Serhant categorizes prospects into hot clients (ready to buy now), warm clients (thinking about buying), and cold clients. Most people give up on clients if they're not ready to buy today.

Serhant follows up with each category, including the cold clients. He sends them articles. He puts their birthday in his calendar. In one instance, he sent a prospect more than 100 follow-ups. When the client was ready to buy, he chose Serhant, who closed a sale that generated a $500,000 commission. It was worth the wait.

2. The Follow-Through

Anyone can send an email. That's a follow-up. Follow-through is the next level. "Do what you say you're going to do," says Serhant. For example, if you say you'll answer emails within 12 hours, do it.

The follow-through reminds me of a wealthy entrepreneur I met a few years ago. "I think you teach at Harvard. I'll put in a call on your behalf," he told me. Honestly, I didn't expect him to follow through. People make promises every day they don't intend to keep. Well, one week later, I received an invitation to teach at Harvard. I turned to my wife and said, "Now I know why this guy's so successful. He does what he says he's going to do."

3. The Follow-Back.

This last step separates the super achievers from the average salespeople. Following back means keeping in touch with clients or--even tougher--past prospects or people who did not hire you. "It's one of the biggest opportunities that salespeople miss out on," writes Serhant. "I can't tell you how many times I've gotten a new client because that person never heard from their broker again after a closing. Ever again."

Think about closing a deal as the beginning of a new chapter in your relationship. After the sale, give your client a call. Ask them how they're enjoying the service or product. A few weeks ago, I spent two days with a Houston hero and philanthropist. On both days, he spent two to three hours calling customers back to see how they enjoyed the product and the service. He was following back.

Yes, success leaves clues, and Serhant has identified some of the specific habits that can turn you into a sales machine. From now on, when you meet someone, don't ask how they can benefit you now; ask how they can benefit your future. That's selling like Serhant.