Two years ago, the 24-year-old Cai was a brand-new college graduate just hoping to eke out a living. Now he runs a tiny international business, buying toys from local factories at ultracheap prices and hawking them on an eBay store. Last winter, he was pulling down $6,000 in monthly sales, with a profit margin as high as 40%, which puts him in the top fifth of earners in China--better than most white- collar workers. Almost 90% of his customers send their payments to him online. "The Internet," he says through a translator, "is how I reach the world." Fast Company