Shoemetro.com, founded in 2004 by Will Huynh, left, and David Duong, grossed $8.9 million last year to earn a spot on Inc. magazine’s 500 fastest-growing private companies list.

Realizing one of their first attempts in business, retailing cell phones, was going nowhere fast, David Duong and Will Huynh began selling shoes online, which has resulted in record-breaking sales.

Last year, San Diego-based Shoemetro.com, which the friends founded in 2004, grossed $8.9 million, up from $5.3 million the year before.

Taking first-year revenue of about $400,000 as a base, Shoemetro.com was ranked No. 86 in Inc. magazine’s 500 fastest-growing companies list released in July. It was also the second fastest-growing Inc. 500 company among 11 that are based in San Diego County.

The two 30-year-old Vietnamese-Americans say they’re proud of their company’s success, but it didn’t come by accident.

“For the past three years, we’ve probably been putting in 12- to 16-hour days, and working six to seven days a week,” said Duong, who came to this country with his parents when he was 1 year old and serves as president.

“A lot of people say we’re lucky, but the harder we work, the luckier we get,” says Huynh, who was 4 years old when his parents arrived from Vietnam, and serves as vice president.

The two friends got involved with a few businesses before focusing on the discount shoe market. Huynh launched a nail salon, and later, the two joined together in a retail phone store in 2003. Duong said after opening the store in Medina, a suburb of Cleveland, four other phone stores opened within a two-mile radius.

The partners were already selling phones and other electronic gadgets online using eBay and Amazon.com, and decided there was more opportunity in selling discount shoes, or those that are discontinued by the manufacturer, or are no longer in season.

Duong and Huynh used about $20,000 of pooled capital to launch the site in 2004. Regarding the rapid sales growth, Duong said the partners had a pretty good brand name on eBay, and as more customers discovered the site, sales grew exponentially. This year, revenue is on track to exceed $12 million.

The company’s staff expanded from the two founders to 26 employees today, with nine coming aboard in the last several months. The firm also just moved into a 36,000-square-foot warehouse in Miramar.

Shoemetro.com carries 80 different brands of shoes, and ships about 900 pairs daily, says Duong. The return rate is only about 5 percent of sales, while some 20 percent of customers are repeat business, Duong said.

While Shoemetro sells both men’s and women’s shoes, the fairer sex generates about 80 percent of the sales. Some men just keep wearing the same pair year after year but women are different, Duong says.

Popular brands offered on Shoemetro.com include Steve Madden, Nine West, BCBG, and Nike.