Susan Gregg-Koger, 27, CEO and Co-founder of ModCloth

Addicted to vintage? So was a young Susan Gregg-Koger. In high school, she would regularly buy retro dresses that weren't her size, just because she was so enamored with their fabric. In college, when her collection started to take over her dorm room, her then boyfriend (and now husband) urged her to cash in on her hoarder habits, and set up an online store where she could sell her eclectic finds. Within a few short years, she went from selling the clothing straight out of her dorm room to having more than 100 employees, and surpassing 15 million dollars in annual revenue.

Photo: Via ModCloth