As a software engineer David Zhao was happy wearing jeans and a T-shirt, day in, day out. After his fashion website launched in 2010, he had to reboot his wardrobe to sweeten his pitch to international luxury brands whose apparel he wanted to hawk online. These days Zhao wears designer knitwear and Italian brogues, a taste of the fancy imported fashion sold on his e-commerce site, Shangpin. But the 40-year-old Beijing CEO is still a geek at heart. “I’m an outsider to fashion circles,” he says. Other entrepreneurs are making a similar journey to the fashion world, lured by the promise...