No question about it, Nasty Gal, the online retailer that caters to a specific set of 20-something girls (think: Rihanna-loving, crop top and Lita-wearing party girls), has blown up over the past year. What started as an one-woman eBay vintage shop in 2006 has turned into a company that reportedly generates $100 million in sales annually and has just under 300 employees. The woman behind it all is 28-year-old Sophia Amoruso. And she's gotten to where she is today partly by doing something all of us do--using social media. We caught up with Amoruso earlier this week at an it-girl filled dinner (Alexandra Richards, Emily Weiss, Mia Moretti, etc., were all in attendance) to celebrate the launch of Nasty Gal shoes, Shoe Cult. She let us pick her brain about how she got started, her latest big hire, and the challenges she's struggling with now that Nasty Gal has exploded.