Sterling Wilson was 22 when he stumbled into the $25 billion promotional products industry during a stint at a Chinese manufacturing firm. Five years later, the company he founded after selling sunglasses to football fans out of his backpack has gone on to attract giant customers including major U.S. university systems and Coca-Cola. The Philadelphia based co-founder of Pop! Promos describes how team spirit and a clever manufacturing regimen has helped his company outplay the competition.

--As told to Melissa Studach

When all my friends were going to study abroad junior year, I didn't see any point in paying tuition to cut class and go travel around Europe. I had seen China in the newspaper every day and decided to take a job with a Chinese pharmaceutical manufacturing firm in Shanghai.

My job was to organize logistics. I learned that there's basically no overnight mail in China. Sending something between provinces could take a couple days, but you could export something out of the country by air to the United States in two days, which was fascinating to me.

I hadn't managed to save a dime living in Shanghai, so when I got back to school for my senior year in 2011 and paid my first and last month's rent and security deposit, suddenly I realized I didn't have a dollar to my name.

I went to the first football game of the year for the University of Southern California, and there were thousands of people tailgating on campus. Everyone's got the hats, shirts, cooler, and koozies, but no one had sunglasses on. I was like, "Oh, my god, this is obvious."

So that night, I got up at midnight after the game--which we won, by the way--and I got on Skype and started calling around. Turns out, the cousin of my old roommate from Shanghai had just bought a sunglasses factory. I designed a pair of sunglasses that were cardinal in color and in gold said 'Game Day' on the sides, and I borrowed some money from my roommate and ordered 2,000 pairs of them.

They showed up, and I made a big sign that said 'Game Day Glasses $10,' got on my bicycle with a backpack full of sunglasses, and sold through 2,000 pairs in three days. I called up a bunch of my high school friends, and they started selling them at their schools. By October, we had quite a little operation going, selling almost 100,000 pairs of sunglasses all over the country.

It quickly shifted from selling glasses out of backpacks to schools coming in and ordering a few thousand pieces at a time. Then we started doing business with some corporate clients, and we had to learn about Food and Drug Administration registration, safety testing, and all these things that we had no concept of.

Eventually our clients started asking us to make products other than glasses. We'd said no for about a year and finally realized that we just had to. Pop! Promos now has a line of about 20 products, and what differentiates us from everyone else in the market is we don't have any inventory--zero. Our ability to never have to say we're out of stock, to perfectly match a color, and to manufacture it from scratch with custom packaging has allowed us to catapult through our industry. I didn't really think much of it when we first started, but when Coca-Cola called up and started ordering from us because we had Coca-Cola red and no one else did, it suddenly clicked.

We've made our place in this business not by looking at things and asking, "How does everyone else do it?" but rather by asking, "What are our options?" How can we do this differently? And by bringing in young people who don't have a ton of experience, we get new ideas.