FORBES - June 29 - Doximity, the San Francisco-based LinkedIn for doctors, popped 69% on its first day as a public company on the NYSE - since then, it's up 115% from its $26 a share offering price. Founded in 2010, Doximity operates a social network for doctors that makes most of its money selling advertising. 80% of its revenue comes from advertisements paid by pharmaceutical companies and hospitals, with the remainder derived from recruiters and telehealth. Doximity's 1.8M members represent 80% of U.S. doctors.